diff --git a/third_party/blink/renderer/SpecMapping.md b/third_party/blink/renderer/SpecMapping.md
index 8fa06e5c63c7e6..0786630ce4cc1c 100644
--- a/third_party/blink/renderer/SpecMapping.md
+++ b/third_party/blink/renderer/SpecMapping.md
@@ -18,15 +18,15 @@ implementation is [LocalFrame].
 [Frame]: https://cs.chromium.org/src/third_party/blink/renderer/core/frame/frame.h
 [LocalFrame]: https://cs.chromium.org/src/third_party/blink/renderer/core/frame/local_frame.h
 
-### [origins](https://html.spec.whatwg.org/multipage/browsers.html#concept-origin)
+### [origins](https://html.spec.whatwg.org/C/#concept-origin)
 
 An origin corresponds to the [SecurityOrigin]. You can test for [same-origin]
 using `SecurityOrigin::canAccess` and for [same-origin domain] using
 `SecurityOrigin::isSameSchemeHostPort`.
 
 [SecurityOrigin]: https://cs.chromium.org/src/third_party/blink/renderer/platform/weborigin/security_origin.h
-[same-origin]: https://html.spec.whatwg.org/multipage/browsers.html#same-origin
-[same-origin domain]: https://html.spec.whatwg.org/multipage/browsers.html#same-origin-domain
+[same-origin]: https://html.spec.whatwg.org/C/#same-origin
+[same-origin domain]: https://html.spec.whatwg.org/C/#same-origin-domain
 
 
 ### [Window object](https://html.spec.whatwg.org/C/#window)
@@ -42,11 +42,11 @@ implementation is [LocalDOMWindow].
 The WindowProxy is part of the bindings implemented by the
 [WindowProxy class](https://cs.chromium.org/Source/bindings/core/v8/WindowProxy.h).
 
-### [canvas](https://html.spec.whatwg.org/multipage/scripting.html#the-canvas-element)
+### [canvas](https://html.spec.whatwg.org/C/#the-canvas-element)
 
 An HTML element into which drawing can be performed imperatively via
 JavaScript. Multiple
-[context types](https://html.spec.whatwg.org/multipage/scripting.html#dom-canvas-getcontext)
+[context types](https://html.spec.whatwg.org/C/#dom-canvas-getcontext)
 are supported for different use cases.
 
 The main element's sources are in [HTMLCanvasElement]. Contexts are implemented
@@ -58,7 +58,7 @@ via modules. The top-level module is [HTMLCanvasElementModule].
 
 The [2D canvas context] is implemented in [modules/canvas2d].
 
-[2D canvas context]: https://html.spec.whatwg.org/multipage/scripting.html#canvasrenderingcontext2d
+[2D canvas context]: https://html.spec.whatwg.org/C/#canvasrenderingcontext2d
 [modules/canvas2d]: https://cs.chromium.org/chromium/src/third_party/blink/renderer/modules/canvas2d/
 
 
diff --git a/third_party/blink/renderer/bindings/IDLExtendedAttributes.md b/third_party/blink/renderer/bindings/IDLExtendedAttributes.md
index bafe30033e9729..59072083782949 100644
--- a/third_party/blink/renderer/bindings/IDLExtendedAttributes.md
+++ b/third_party/blink/renderer/bindings/IDLExtendedAttributes.md
@@ -142,10 +142,10 @@ Undocumented: `[TreatNonObjectAsNull]`
 
 ### [CEReactions] _(m, a)_
 
-Standard: [CEReactions](https://html.spec.whatwg.org/multipage/scripting.html#cereactions)
+Standard: [CEReactions](https://html.spec.whatwg.org/C/#cereactions)
 
 Summary: `[CEReactions]` indicates that
-[custom element reactions](https://html.spec.whatwg.org/multipage/scripting.html#concept-custom-element-reaction)
+[custom element reactions](https://html.spec.whatwg.org/C/#concept-custom-element-reaction)
 are triggered for this method or attribute.
 
 Usage: `[CEReactions]` takes no arguments.
@@ -304,7 +304,7 @@ The identifier argument or identifier list argument the `[Global]` extended attr
 
 ### [HTMLConstructor]
 
-Standard: [HTMLConstructor](https://html.spec.whatwg.org/multipage/dom.html#html-element-constructors)
+Standard: [HTMLConstructor](https://html.spec.whatwg.org/C/#html-element-constructors)
 
 Summary: HTML Elements have special constructor behavior. Interface object of given interface with the `[HTMLConstructor]` attribute will have specific behavior when called.
 
@@ -484,7 +484,7 @@ interface Window {
 
 ### [Serializable] _(i)_
 
-Standard: [Serializable](https://html.spec.whatwg.org/multipage/structured-data.html#serializable)
+Standard: [Serializable](https://html.spec.whatwg.org/C/#serializable)
 
 Summary: Serializable objects support being serialized, and later deserialized, for persistence in storage APIs or for passing with `postMessage()`.
 
@@ -498,7 +498,7 @@ This attribute has no effect on code generation and should simply be used in Bli
 
 ### [Transferable] _(i)_
 
-Standard: [Transferable](https://html.spec.whatwg.org/multipage/structured-data.html#transferable)
+Standard: [Transferable](https://html.spec.whatwg.org/C/#transferable)
 
 Summary: Transferable objects support being transferred across Realms with `postMessage()`.
 
@@ -1656,4 +1656,4 @@ Redistribution and use in source and binary forms, with or without modification,
 THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ***
 
-[CrossOriginProperties]: https://html.spec.whatwg.org/multipage/browsers.html#crossoriginproperties-(-o-)
+[CrossOriginProperties]: https://html.spec.whatwg.org/C/#crossoriginproperties-(-o-)
diff --git a/third_party/blink/renderer/bindings/core/v8/V8BindingDesign.md b/third_party/blink/renderer/bindings/core/v8/V8BindingDesign.md
index 451055b6e5fe64..6c483b89cd1f5e 100644
--- a/third_party/blink/renderer/bindings/core/v8/V8BindingDesign.md
+++ b/third_party/blink/renderer/bindings/core/v8/V8BindingDesign.md
@@ -117,9 +117,9 @@ the entered context is the context of the main frame
 (not the context of `<iframe>`).
 
 The entered context is a concept to implement the
-[entry settings object](https://html.spec.whatwg.org/multipage/webappapis.html#entry-settings-object)
+[entry settings object](https://html.spec.whatwg.org/C/#entry-settings-object)
 of the HTML spec. The current context is a concept to implement the
-[incumbent settings object](https://html.spec.whatwg.org/multipage/webappapis.html#incumbent-settings-object)
+[incumbent settings object](https://html.spec.whatwg.org/C/#incumbent-settings-object)
 of the HTML spec.
 
 In summary, the entered context is a context from which the current JavaScript
diff --git a/third_party/blink/renderer/bindings/core/v8/binding_security.cc b/third_party/blink/renderer/bindings/core/v8/binding_security.cc
index b720ebd7642483..85c207310a6b6a 100644
--- a/third_party/blink/renderer/bindings/core/v8/binding_security.cc
+++ b/third_party/blink/renderer/bindings/core/v8/binding_security.cc
@@ -385,7 +385,7 @@ bool BindingSecurity::ShouldAllowWrapperCreationOrThrowException(
     return true;
 
   // According to
-  // https://html.spec.whatwg.org/multipage/browsers.html#security-location,
+  // https://html.spec.whatwg.org/C/#security-location,
   // cross-origin script access to a few properties of Location is allowed.
   // Location already implements the necessary security checks.
   if (wrapper_type_info->Equals(V8Location::GetWrapperTypeInfo()))
diff --git a/third_party/blink/renderer/bindings/core/v8/custom/v8_window_custom.cc b/third_party/blink/renderer/bindings/core/v8/custom/v8_window_custom.cc
index b87d4471fcee9e..f3c5c8d2b1f4a4 100644
--- a/third_party/blink/renderer/bindings/core/v8/custom/v8_window_custom.cc
+++ b/third_party/blink/renderer/bindings/core/v8/custom/v8_window_custom.cc
@@ -210,11 +210,11 @@ void V8Window::NamedPropertyGetterCustom(
 
   // Note that named access on WindowProxy is allowed in the cross-origin case.
   // 7.4.5 [[GetOwnProperty]] (P), step 6.
-  // https://html.spec.whatwg.org/multipage/browsers.html#windowproxy-getownproperty
+  // https://html.spec.whatwg.org/C/#windowproxy-getownproperty
   //
   // 7.3.3 Named access on the Window object
   // The document-tree child browsing context name property set
-  // https://html.spec.whatwg.org/multipage/browsers.html#document-tree-child-browsing-context-name-property-set
+  // https://html.spec.whatwg.org/C/#document-tree-child-browsing-context-name-property-set
   Frame* child = frame->Tree().ScopedChild(name);
   if (child) {
     UseCounter::Count(CurrentExecutionContext(info.GetIsolate()),
@@ -252,7 +252,7 @@ void V8Window::NamedPropertyGetterCustom(
           CurrentDOMWindow(info.GetIsolate()), window,
           BindingSecurity::ErrorReportOption::kDoNotReport)) {
     // HTML 7.2.3.3 CrossOriginGetOwnPropertyHelper ( O, P )
-    // https://html.spec.whatwg.org/multipage/browsers.html#crossorigingetownpropertyhelper-(-o,-p-)
+    // https://html.spec.whatwg.org/C/#crossorigingetownpropertyhelper-(-o,-p-)
     // step 3. If P is "then", @@toStringTag, @@hasInstance, or
     //   @@isConcatSpreadable, then return PropertyDescriptor{ [[Value]]:
     //   undefined, [[Writable]]: false, [[Enumerable]]: false,
diff --git a/third_party/blink/renderer/bindings/core/v8/js_based_event_listener.cc b/third_party/blink/renderer/bindings/core/v8/js_based_event_listener.cc
index c3bacc5e74857f..bb9e376903546f 100644
--- a/third_party/blink/renderer/bindings/core/v8/js_based_event_listener.cc
+++ b/third_party/blink/renderer/bindings/core/v8/js_based_event_listener.cc
@@ -76,7 +76,7 @@ void JSBasedEventListener::Invoke(
     // order, which says it should be done in step 10. There is no behavioral
     // difference but the advantage that we can use listener's |ScriptState|
     // after it get compiled.
-    // https://html.spec.whatwg.org/multipage/webappapis.html#event-handler-value
+    // https://html.spec.whatwg.org/C/#event-handler-value
     v8::Local<v8::Value> listener = GetListenerObject(*event->currentTarget());
 
     if (listener.IsEmpty() || !listener->IsObject())
diff --git a/third_party/blink/renderer/bindings/core/v8/js_based_event_listener.h b/third_party/blink/renderer/bindings/core/v8/js_based_event_listener.h
index 1e47648243cf6b..ed489c7fe36d88 100644
--- a/third_party/blink/renderer/bindings/core/v8/js_based_event_listener.h
+++ b/third_party/blink/renderer/bindings/core/v8/js_based_event_listener.h
@@ -36,7 +36,7 @@ class CORE_EXPORT JSBasedEventListener : public EventListener {
   // content attribute to get compiled, potentially unsuccessfully.
   //
   // Implements "get the current value of the event handler".
-  // https://html.spec.whatwg.org/multipage/webappapis.html#getting-the-current-value-of-the-event-handler
+  // https://html.spec.whatwg.org/C/#getting-the-current-value-of-the-event-handler
   // Returns v8::Null with firing error event instead of throwing an exception
   // on failing to compile the uncompiled script body in eventHandler's value.
   // Also, this can return empty because of crbug.com/881688 .
diff --git a/third_party/blink/renderer/bindings/core/v8/js_event_handler.cc b/third_party/blink/renderer/bindings/core/v8/js_event_handler.cc
index ab11c080eaa4fc..4cd2b2c06af611 100644
--- a/third_party/blink/renderer/bindings/core/v8/js_event_handler.cc
+++ b/third_party/blink/renderer/bindings/core/v8/js_event_handler.cc
@@ -34,7 +34,7 @@ void JSEventHandler::SetCompiledHandler(ScriptState* incumbent_script_state,
                                         v8::Local<v8::Function> listener) {
   DCHECK(!HasCompiledHandler());
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#getting-the-current-value-of-the-event-handler
+  // https://html.spec.whatwg.org/C/#getting-the-current-value-of-the-event-handler
   // Step 12: Set eventHandler's value to the result of creating a Web IDL
   // EventHandler callback function object whose object reference is function
   // and whose callback context is settings object.
diff --git a/third_party/blink/renderer/bindings/core/v8/js_event_handler_for_content_attribute.cc b/third_party/blink/renderer/bindings/core/v8/js_event_handler_for_content_attribute.cc
index cfc41316c7b650..8a556264f9e248 100644
--- a/third_party/blink/renderer/bindings/core/v8/js_event_handler_for_content_attribute.cc
+++ b/third_party/blink/renderer/bindings/core/v8/js_event_handler_for_content_attribute.cc
@@ -27,7 +27,7 @@ v8::Local<v8::Value> JSEventHandlerForContentAttribute::GetListenerObject(
 }
 
 // Implements Step 3. of "get the current value of the event handler"
-// https://html.spec.whatwg.org/multipage/webappapis.html#getting-the-current-value-of-the-event-handler
+// https://html.spec.whatwg.org/C/#getting-the-current-value-of-the-event-handler
 v8::Local<v8::Value> JSEventHandlerForContentAttribute::GetCompiledHandler(
     EventTarget& event_target) {
   // Do not compile the same code twice.
diff --git a/third_party/blink/renderer/bindings/core/v8/js_event_handler_for_content_attribute.h b/third_party/blink/renderer/bindings/core/v8/js_event_handler_for_content_attribute.h
index bf3af88097c744..66aba9acc361c7 100644
--- a/third_party/blink/renderer/bindings/core/v8/js_event_handler_for_content_attribute.h
+++ b/third_party/blink/renderer/bindings/core/v8/js_event_handler_for_content_attribute.h
@@ -66,7 +66,7 @@ class JSEventHandlerForContentAttribute final : public JSEventHandler {
   // The compiled v8::Function is returned and |JSEventHandler::event_handler_|
   // gets initialized with it if lazy compilation succeeds.
   // Otherwise, v8::Null is returned.
-  // https://html.spec.whatwg.org/multipage/webappapis.html#getting-the-current-value-of-the-event-handler
+  // https://html.spec.whatwg.org/C/#getting-the-current-value-of-the-event-handler
   v8::Local<v8::Value> GetCompiledHandler(EventTarget&);
 
   // Lazy compilation for content attribute should be tried only once, but we
diff --git a/third_party/blink/renderer/bindings/core/v8/referrer_script_info.h b/third_party/blink/renderer/bindings/core/v8/referrer_script_info.h
index 93e544b8269693..2a3cef600a8df9 100644
--- a/third_party/blink/renderer/bindings/core/v8/referrer_script_info.h
+++ b/third_party/blink/renderer/bindings/core/v8/referrer_script_info.h
@@ -17,7 +17,7 @@ namespace blink {
 
 // ReferrerScriptInfo carries a copy of "referencing script's" info referenced
 // in HTML Spec: "HostImportModuleDynamically" algorithm.
-// https://html.spec.whatwg.org/multipage/webappapis.html#hostimportmoduledynamically(referencingscriptormodule,-specifier,-promisecapability)
+// https://html.spec.whatwg.org/C/#hostimportmoduledynamically(referencingscriptormodule,-specifier,-promisecapability)
 class CORE_EXPORT ReferrerScriptInfo {
  public:
   ReferrerScriptInfo() {}
@@ -62,7 +62,7 @@ class CORE_EXPORT ReferrerScriptInfo {
 
  private:
   // Spec: "referencing script's base URL"
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-base-url
+  // https://html.spec.whatwg.org/C/#concept-script-base-url
   //
   // If base_url_.IsNull(), refer to ScriptOrigin::ResourceName() instead.
   // Note: This improves the chance of getting into the fast path in
@@ -71,7 +71,7 @@ class CORE_EXPORT ReferrerScriptInfo {
 
   // Spec: "referencing script's credentials mode"
   // The default value is "same-origin" per:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#default-classic-script-fetch-options
+  // https://html.spec.whatwg.org/C/#default-classic-script-fetch-options
   const network::mojom::FetchCredentialsMode credentials_mode_ =
       network::mojom::FetchCredentialsMode::kSameOrigin;
 
@@ -80,12 +80,12 @@ class CORE_EXPORT ReferrerScriptInfo {
 
   // Spec: "referencing script's parser state"
   // The default value is "not-parser-inserted" per:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#default-classic-script-fetch-options
+  // https://html.spec.whatwg.org/C/#default-classic-script-fetch-options
   const ParserDisposition parser_state_ = kNotParserInserted;
 
   // Spec: "referencing script's referrer policy"
   // The default value is "the empty string" per:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#default-classic-script-fetch-options
+  // https://html.spec.whatwg.org/C/#default-classic-script-fetch-options
   const network::mojom::ReferrerPolicy referrer_policy_ =
       network::mojom::ReferrerPolicy::kDefault;
 };
diff --git a/third_party/blink/renderer/bindings/core/v8/script_controller.cc b/third_party/blink/renderer/bindings/core/v8/script_controller.cc
index 3151eb6134632d..abaa977cb62a90 100644
--- a/third_party/blink/renderer/bindings/core/v8/script_controller.cc
+++ b/third_party/blink/renderer/bindings/core/v8/script_controller.cc
@@ -249,7 +249,7 @@ bool ScriptController::ExecuteScriptIfJavaScriptURL(
 
   v8::HandleScope handle_scope(GetIsolate());
 
-  // https://html.spec.whatwg.org/multipage/browsing-the-web.html#navigate
+  // https://html.spec.whatwg.org/C/#navigate
   // Step 12.8 "Let base URL be settings object's API base URL." [spec text]
   KURL base_url = owner_document->BaseURL();
 
diff --git a/third_party/blink/renderer/bindings/core/v8/script_custom_element_definition.cc b/third_party/blink/renderer/bindings/core/v8/script_custom_element_definition.cc
index 0f49d3ad74a226..828f6f7d043fcd 100644
--- a/third_party/blink/renderer/bindings/core/v8/script_custom_element_definition.cc
+++ b/third_party/blink/renderer/bindings/core/v8/script_custom_element_definition.cc
@@ -200,7 +200,7 @@ HTMLElement* ScriptCustomElementDefinition::CreateAutonomousCustomElementSync(
   return ToHTMLElement(element);
 }
 
-// https://html.spec.whatwg.org/multipage/scripting.html#upgrades
+// https://html.spec.whatwg.org/C/#upgrades
 bool ScriptCustomElementDefinition::RunConstructor(Element& element) {
   if (!script_state_->ContextIsValid())
     return false;
diff --git a/third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.h b/third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.h
index 0702f58f0bc690..2a6b2a58dfda7d 100644
--- a/third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.h
+++ b/third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.h
@@ -110,7 +110,7 @@ class CORE_EXPORT SerializedScriptValue
   // This enumeration specifies whether we're serializing a value for storage;
   // e.g. when writing to IndexedDB. This corresponds to the forStorage flag of
   // the HTML spec:
-  // https://html.spec.whatwg.org/multipage/infrastructure.html#safe-passing-of-structured-data
+  // https://html.spec.whatwg.org/C/#safe-passing-of-structured-data
   enum StoragePolicy {
     // Not persisted; used only during the execution of the browser.
     kNotForStorage,
diff --git a/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.cc b/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.cc
index 19b2d96dc163fb..e382130d2a003d 100644
--- a/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.cc
+++ b/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.cc
@@ -145,7 +145,7 @@ void V8ScriptValueSerializer::FinalizeTransfer(
     ExceptionState& exception_state) {
   // TODO(jbroman): Strictly speaking, this is not correct; transfer should
   // occur in the order of the transfer list.
-  // https://html.spec.whatwg.org/multipage/infrastructure.html#structuredclonewithtransfer
+  // https://html.spec.whatwg.org/C/#structuredclonewithtransfer
 
   v8::Isolate* isolate = script_state_->GetIsolate();
 
diff --git a/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.h b/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.h
index e159a1e0115b68..3cc048a22b8162 100644
--- a/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.h
+++ b/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.h
@@ -23,7 +23,7 @@ class File;
 class Transferables;
 
 // Serializes V8 values according to the HTML structured clone algorithm:
-// https://html.spec.whatwg.org/multipage/infrastructure.html#structured-clone
+// https://html.spec.whatwg.org/C/#structured-clone
 //
 // Supports only basic JavaScript objects and core DOM types. Support for
 // modules types is implemented in a subclass.
diff --git a/third_party/blink/renderer/bindings/core/v8/v8_html_constructor.cc b/third_party/blink/renderer/bindings/core/v8/v8_html_constructor.cc
index 1a0d6564935edd..ea5352504bc27c 100644
--- a/third_party/blink/renderer/bindings/core/v8/v8_html_constructor.cc
+++ b/third_party/blink/renderer/bindings/core/v8/v8_html_constructor.cc
@@ -21,7 +21,7 @@
 
 namespace blink {
 
-// https://html.spec.whatwg.org/multipage/dom.html#html-element-constructors
+// https://html.spec.whatwg.org/C/#html-element-constructors
 void V8HTMLConstructor::HtmlConstructor(
     const v8::FunctionCallbackInfo<v8::Value>& info,
     const WrapperTypeInfo& wrapper_type_info,
diff --git a/third_party/blink/renderer/bindings/core/v8/v8_html_constructor.h b/third_party/blink/renderer/bindings/core/v8/v8_html_constructor.h
index a8f2ec409e274f..784f4aab7a36cf 100644
--- a/third_party/blink/renderer/bindings/core/v8/v8_html_constructor.h
+++ b/third_party/blink/renderer/bindings/core/v8/v8_html_constructor.h
@@ -11,7 +11,7 @@
 
 namespace blink {
 
-// https://html.spec.whatwg.org/multipage/dom.html#html-element-constructors
+// https://html.spec.whatwg.org/C/#html-element-constructors
 class CORE_EXPORT V8HTMLConstructor {
   STATIC_ONLY(V8HTMLConstructor);
 
diff --git a/third_party/blink/renderer/bindings/core/v8/v8_script_runner.cc b/third_party/blink/renderer/bindings/core/v8/v8_script_runner.cc
index 796219bf88b549..f94ce5ce479b85 100644
--- a/third_party/blink/renderer/bindings/core/v8/v8_script_runner.cc
+++ b/third_party/blink/renderer/bindings/core/v8/v8_script_runner.cc
@@ -459,7 +459,7 @@ void V8ScriptRunner::ReportException(v8::Isolate* isolate,
                                      v8::Local<v8::Value> exception) {
   DCHECK(!exception.IsEmpty());
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#report-the-error
+  // https://html.spec.whatwg.org/C/#report-the-error
   v8::Local<v8::Message> message =
       v8::Exception::CreateMessage(isolate, exception);
   if (IsMainThread())
diff --git a/third_party/blink/renderer/bindings/scripts/v8_interface.py b/third_party/blink/renderer/bindings/scripts/v8_interface.py
index 7ea0940c744c03..65160189e245f5 100644
--- a/third_party/blink/renderer/bindings/scripts/v8_interface.py
+++ b/third_party/blink/renderer/bindings/scripts/v8_interface.py
@@ -333,7 +333,7 @@ def interface_context(interface, interfaces):
 
     # [HTMLConstructor]
     has_html_constructor = 'HTMLConstructor' in extended_attributes
-    # https://html.spec.whatwg.org/multipage/dom.html#html-element-constructors
+    # https://html.spec.whatwg.org/C/#html-element-constructors
     if has_html_constructor:
         if ('Constructor' in extended_attributes) or ('NoInterfaceObject' in extended_attributes):
             raise Exception('[Constructor] and [NoInterfaceObject] MUST NOT be'
diff --git a/third_party/blink/renderer/bindings/scripts/v8_methods.py b/third_party/blink/renderer/bindings/scripts/v8_methods.py
index f63b86a3f1effa..6d067908de1e6f 100644
--- a/third_party/blink/renderer/bindings/scripts/v8_methods.py
+++ b/third_party/blink/renderer/bindings/scripts/v8_methods.py
@@ -434,7 +434,7 @@ def v8_value_to_local_cpp_value(interface_name, method, argument, index):
 
     # History.pushState and History.replaceState are explicitly specified as
     # serializing the value for storage. The default is to not serialize for
-    # storage. See https://html.spec.whatwg.org/multipage/browsers.html#dom-history-pushstate
+    # storage. See https://html.spec.whatwg.org/C/#dom-history-pushstate
     if idl_type.name == 'SerializedScriptValue':
         for_storage = (interface_name == 'History' and
                        method.name in ('pushState', 'replaceState'))
diff --git a/third_party/blink/renderer/bindings/templates/interface_base.cc.tmpl b/third_party/blink/renderer/bindings/templates/interface_base.cc.tmpl
index 91e2184d0193b6..e7369089c89a3a 100644
--- a/third_party/blink/renderer/bindings/templates/interface_base.cc.tmpl
+++ b/third_party/blink/renderer/bindings/templates/interface_base.cc.tmpl
@@ -280,7 +280,7 @@ void {{v8_class_or_partial}}::CrossOriginNamedGetter(v8::Local<v8::Name> name, c
   {% endif %}
   {% else %}
   // HTML 7.2.3.3 CrossOriginGetOwnPropertyHelper ( O, P )
-  // https://html.spec.whatwg.org/multipage/browsers.html#crossorigingetownpropertyhelper-(-o,-p-)
+  // https://html.spec.whatwg.org/C/#crossorigingetownpropertyhelper-(-o,-p-)
   // step 3. If P is "then", @@toStringTag, @@hasInstance, or
   //   @@isConcatSpreadable, then return PropertyDescriptor{ [[Value]]:
   //   undefined, [[Writable]]: false, [[Enumerable]]: false,
diff --git a/third_party/blink/renderer/bindings/tests/results/core/v8_test_interface_check_security.cc b/third_party/blink/renderer/bindings/tests/results/core/v8_test_interface_check_security.cc
index 1f69fb6536c678..09f91b9f8bb30b 100644
--- a/third_party/blink/renderer/bindings/tests/results/core/v8_test_interface_check_security.cc
+++ b/third_party/blink/renderer/bindings/tests/results/core/v8_test_interface_check_security.cc
@@ -734,7 +734,7 @@ void V8TestInterfaceCheckSecurity::CrossOriginNamedGetter(v8::Local<v8::Name> na
   }
 
   // HTML 7.2.3.3 CrossOriginGetOwnPropertyHelper ( O, P )
-  // https://html.spec.whatwg.org/multipage/browsers.html#crossorigingetownpropertyhelper-(-o,-p-)
+  // https://html.spec.whatwg.org/C/#crossorigingetownpropertyhelper-(-o,-p-)
   // step 3. If P is "then", @@toStringTag, @@hasInstance, or
   //   @@isConcatSpreadable, then return PropertyDescriptor{ [[Value]]:
   //   undefined, [[Writable]]: false, [[Enumerable]]: false,
diff --git a/third_party/blink/renderer/core/css/properties/longhands/text_align_custom.cc b/third_party/blink/renderer/core/css/properties/longhands/text_align_custom.cc
index 4377366d66d4d0..d029aee52774c2 100644
--- a/third_party/blink/renderer/core/css/properties/longhands/text_align_custom.cc
+++ b/third_party/blink/renderer/core/css/properties/longhands/text_align_custom.cc
@@ -22,7 +22,7 @@ void TextAlign::ApplyValue(StyleResolverState& state,
       ToCSSIdentifierValue(value).GetValueID() != CSSValueWebkitMatchParent) {
     // Special case for th elements - UA stylesheet text-align does not apply if
     // parent's computed value for text-align is not its initial value
-    // https://html.spec.whatwg.org/multipage/rendering.html#tables-2
+    // https://html.spec.whatwg.org/C/#tables-2
     const CSSIdentifierValue& ident_value = ToCSSIdentifierValue(value);
     if (ident_value.GetValueID() == CSSValueInternalCenter &&
         state.ParentStyle()->GetTextAlign() !=
diff --git a/third_party/blink/renderer/core/css/resolver/style_adjuster.cc b/third_party/blink/renderer/core/css/resolver/style_adjuster.cc
index 0b552a69d2bf83..a358499ad93648 100644
--- a/third_party/blink/renderer/core/css/resolver/style_adjuster.cc
+++ b/third_party/blink/renderer/core/css/resolver/style_adjuster.cc
@@ -196,7 +196,7 @@ static bool DoesNotInheritTextDecoration(const ComputedStyle& style,
 // Certain elements (<a>, <font>) override text decoration colors.  "The font
 // element is expected to override the color of any text decoration that spans
 // the text of the element to the used value of the element's 'color' property."
-// (https://html.spec.whatwg.org/multipage/rendering.html#phrasing-content-3)
+// (https://html.spec.whatwg.org/C/#phrasing-content-3)
 // The <a> behavior is non-standard.
 static bool OverridesTextDecorationColors(const Element* element) {
   return element &&
diff --git a/third_party/blink/renderer/core/dom/character_data.cc b/third_party/blink/renderer/core/dom/character_data.cc
index 956c1942c27423..61389c52166c34 100644
--- a/third_party/blink/renderer/core/dom/character_data.cc
+++ b/third_party/blink/renderer/core/dom/character_data.cc
@@ -227,7 +227,7 @@ void CharacterData::DidModifyData(const String& old_data, UpdateSource source) {
 
   // Skip DOM mutation events if the modification is from parser.
   // Note that mutation observer events will still fire.
-  // Spec: https://html.spec.whatwg.org/multipage/syntax.html#insert-a-character
+  // Spec: https://html.spec.whatwg.org/C/#insert-a-character
   if (source != kUpdateFromParser && !IsInShadowTree()) {
     if (GetDocument().HasListenerType(
             Document::kDOMCharacterDataModifiedListener)) {
diff --git a/third_party/blink/renderer/core/dom/document.cc b/third_party/blink/renderer/core/dom/document.cc
index 88c0cdcc718084..b49208fe5635e5 100644
--- a/third_party/blink/renderer/core/dom/document.cc
+++ b/third_party/blink/renderer/core/dom/document.cc
@@ -932,7 +932,7 @@ Element* Document::CreateRawElement(const QualifiedName& qname,
                                     CreateElementFlags flags) {
   Element* element = nullptr;
   if (qname.NamespaceURI() == html_names::xhtmlNamespaceURI) {
-    // https://html.spec.whatwg.org/multipage/dom.html#elements-in-the-dom:element-interface
+    // https://html.spec.whatwg.org/C/#elements-in-the-dom:element-interface
     element = HTMLElementFactory::Create(qname.LocalName(), *this, flags);
     if (!element) {
       // 6. If name is a valid custom element name, then return
@@ -4341,7 +4341,7 @@ network::mojom::ReferrerPolicy Document::GetReferrerPolicy() const {
   // For srcdoc documents without their own policy, walk up the frame
   // tree to find the document that is either not a srcdoc or doesn't
   // have its own policy. This algorithm is defined in
-  // https://html.spec.whatwg.org/multipage/window-object.html#set-up-a-window-environment-settings-object.
+  // https://html.spec.whatwg.org/C/#set-up-a-window-environment-settings-object.
   if (!frame_ || policy != network::mojom::ReferrerPolicy::kDefault ||
       !IsSrcdocDocument()) {
     return policy;
@@ -5848,7 +5848,7 @@ KURL Document::CompleteURLWithOverride(const String& url,
 
 // static
 bool Document::ShouldInheritSecurityOriginFromOwner(const KURL& url) {
-  // https://html.spec.whatwg.org/multipage/browsers.html#origin
+  // https://html.spec.whatwg.org/C/#origin
   //
   // If a Document is the initial "about:blank" document The origin and
   // effective script origin of the Document are those it was assigned when its
diff --git a/third_party/blink/renderer/core/dom/document.h b/third_party/blink/renderer/core/dom/document.h
index 8818beaddd97f4..13e9412ff162f4 100644
--- a/third_party/blink/renderer/core/dom/document.h
+++ b/third_party/blink/renderer/core/dom/document.h
@@ -681,7 +681,7 @@ class CORE_EXPORT Document : public ContainerNode,
   // comments surrounding their declaration.
 
   // Document base URL.
-  // https://html.spec.whatwg.org/multipage/urls-and-fetching.html#document-base-url
+  // https://html.spec.whatwg.org/C/#document-base-url
   const KURL& BaseURL() const final;
   void SetBaseURLOverride(const KURL&);
   const KURL& BaseURLOverride() const { return base_url_override_; }
@@ -690,7 +690,7 @@ class CORE_EXPORT Document : public ContainerNode,
   void ProcessBaseElement();
 
   // Fallback base URL.
-  // https://html.spec.whatwg.org/multipage/urls-and-fetching.html#fallback-base-url
+  // https://html.spec.whatwg.org/C/#fallback-base-url
   KURL FallbackBaseURL() const;
 
   // Creates URL based on passed relative url and this documents base URL.
@@ -743,7 +743,7 @@ class CORE_EXPORT Document : public ContainerNode,
   bool InNoQuirksMode() const { return compatibility_mode_ == kNoQuirksMode; }
   bool InLineHeightQuirksMode() const { return !InNoQuirksMode(); }
 
-  // https://html.spec.whatwg.org/multipage/dom.html#documentreadystate
+  // https://html.spec.whatwg.org/C/#documentreadystate
   enum DocumentReadyState { kLoading, kInteractive, kComplete };
 
   void SetReadyState(DocumentReadyState);
@@ -969,7 +969,7 @@ class CORE_EXPORT Document : public ContainerNode,
   static bool HasValidNamespaceForAttributes(const QualifiedName&);
 
   // "body element" as defined by HTML5
-  // (https://html.spec.whatwg.org/multipage/dom.html#the-body-element-2).
+  // (https://html.spec.whatwg.org/C/#the-body-element-2).
   // That is, the first body or frameset child of the document element.
   HTMLElement* body() const;
 
@@ -1490,7 +1490,7 @@ class CORE_EXPORT Document : public ContainerNode,
   // TODO(binji): See http://crbug.com/798572. This implementation shares the
   // same agent cluster ID for any one document. The proper implementation of
   // this function must follow the rules described here:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#integration-with-the-javascript-agent-cluster-formalism.
+  // https://html.spec.whatwg.org/C/#integration-with-the-javascript-agent-cluster-formalism.
   //
   // Even with this simple implementation, we can prevent sharing
   // SharedArrayBuffers and WebAssembly modules with workers that happen to be
diff --git a/third_party/blink/renderer/core/dom/document_and_element_event_handlers.idl b/third_party/blink/renderer/core/dom/document_and_element_event_handlers.idl
index c1b1362a6b335b..a42404fc0d0d70 100644
--- a/third_party/blink/renderer/core/dom/document_and_element_event_handlers.idl
+++ b/third_party/blink/renderer/core/dom/document_and_element_event_handlers.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#documentandelementeventhandlers
+// https://html.spec.whatwg.org/C/#documentandelementeventhandlers
 
 [
     LegacyTreatAsPartialInterface,
diff --git a/third_party/blink/renderer/core/dom/dom_string_list.idl b/third_party/blink/renderer/core/dom/dom_string_list.idl
index aabd5f54145659..4be5453d073169 100644
--- a/third_party/blink/renderer/core/dom/dom_string_list.idl
+++ b/third_party/blink/renderer/core/dom/dom_string_list.idl
@@ -23,7 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/infrastructure.html#domstringlist
+// https://html.spec.whatwg.org/C/#domstringlist
 
 [Exposed=(Window,Worker)]
 interface DOMStringList {
diff --git a/third_party/blink/renderer/core/dom/element.h b/third_party/blink/renderer/core/dom/element.h
index 0070e18ef8e6c3..f16e254d4f10ba 100644
--- a/third_party/blink/renderer/core/dom/element.h
+++ b/third_party/blink/renderer/core/dom/element.h
@@ -115,7 +115,7 @@ enum class SelectionBehaviorOnFocus {
   kNone,
 };
 
-// https://html.spec.whatwg.org/multipage/dom.html#dom-document-nameditem-filter
+// https://html.spec.whatwg.org/C/#dom-document-nameditem-filter
 enum class NamedItemType {
   kNone,
   kName,
@@ -780,7 +780,7 @@ class CORE_EXPORT Element : public ContainerNode {
 
   // Elements that may have an insertion mode other than "in body" should
   // override this and return true.
-  // https://html.spec.whatwg.org/multipage/parsing.html#reset-the-insertion-mode-appropriately
+  // https://html.spec.whatwg.org/C/#reset-the-insertion-mode-appropriately
   virtual bool HasNonInBodyInsertionMode() const { return false; }
 
   bool CanContainRangeEndPoint() const override { return true; }
diff --git a/third_party/blink/renderer/core/dom/frame_request_callback.idl b/third_party/blink/renderer/core/dom/frame_request_callback.idl
index 927a889435c6d6..4640fec26f3cac 100644
--- a/third_party/blink/renderer/core/dom/frame_request_callback.idl
+++ b/third_party/blink/renderer/core/dom/frame_request_callback.idl
@@ -28,6 +28,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/window-object.html#framerequestcallback
+// https://html.spec.whatwg.org/C/#framerequestcallback
 
 callback FrameRequestCallback = void(DOMHighResTimeStamp highResTime);
diff --git a/third_party/blink/renderer/core/dom/mutation_observer.cc b/third_party/blink/renderer/core/dom/mutation_observer.cc
index a14b7aa53e7bbd..e15b9e3366d6ff 100644
--- a/third_party/blink/renderer/core/dom/mutation_observer.cc
+++ b/third_party/blink/renderer/core/dom/mutation_observer.cc
@@ -231,7 +231,7 @@ using SlotChangeList = HeapVector<Member<HTMLSlotElement>>;
 
 // TODO(hayato): We should have a SlotChangeList for each unit of related
 // similar-origin browsing context.
-// https://html.spec.whatwg.org/multipage/browsers.html#unit-of-related-similar-origin-browsing-contexts
+// https://html.spec.whatwg.org/C/#unit-of-related-similar-origin-browsing-contexts
 static SlotChangeList& ActiveSlotChangeList() {
   DEFINE_STATIC_LOCAL(Persistent<SlotChangeList>, slot_change_list,
                       (MakeGarbageCollected<SlotChangeList>()));
diff --git a/third_party/blink/renderer/core/dom/node.h b/third_party/blink/renderer/core/dom/node.h
index 20dc728d7a2666..1c39afef70ef2f 100644
--- a/third_party/blink/renderer/core/dom/node.h
+++ b/third_party/blink/renderer/core/dom/node.h
@@ -570,7 +570,7 @@ class CORE_EXPORT Node : public EventTarget {
   virtual bool ShouldHaveFocusAppearance() const;
 
   // Whether the node is inert:
-  // https://html.spec.whatwg.org/multipage/interaction.html#inert
+  // https://html.spec.whatwg.org/C/#inert
   // https://github.com/WICG/inert/blob/master/README.md
   // This can't be in Element because text nodes must be recognized as
   // inert to prevent text selection.
diff --git a/third_party/blink/renderer/core/dom/scripted_animation_controller.h b/third_party/blink/renderer/core/dom/scripted_animation_controller.h
index 6b088872d3316a..bb9d9cdcaac417 100644
--- a/third_party/blink/renderer/core/dom/scripted_animation_controller.h
+++ b/third_party/blink/renderer/core/dom/scripted_animation_controller.h
@@ -78,7 +78,7 @@ class CORE_EXPORT ScriptedAnimationController
       HeapVector<Member<MediaQueryListListener>>&);
 
   // Invokes callbacks, dispatches events, etc. The order is defined by HTML:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#event-loop-processing-model
+  // https://html.spec.whatwg.org/C/#event-loop-processing-model
   void ServiceScriptedAnimations(base::TimeTicks monotonic_time_now);
 
   void Pause();
diff --git a/third_party/blink/renderer/core/editing/element_inner_text.cc b/third_party/blink/renderer/core/editing/element_inner_text.cc
index a4073909eb6c4d..3374096c6010ad 100644
--- a/third_party/blink/renderer/core/editing/element_inner_text.cc
+++ b/third_party/blink/renderer/core/editing/element_inner_text.cc
@@ -35,7 +35,7 @@ namespace {
 
 // The implementation of Element#innerText algorithm[1].
 // [1]
-// https://html.spec.whatwg.org/multipage/dom.html#the-innertext-idl-attribute
+// https://html.spec.whatwg.org/C/#the-innertext-idl-attribute
 class ElementInnerTextCollector final {
  public:
   ElementInnerTextCollector() = default;
@@ -137,7 +137,7 @@ bool ElementInnerTextCollector::HasDisplayContentsStyle(const Node& node) {
 // Note: Just being off-screen does not mean the element is not being rendered.
 // The presence of the "hidden" attribute normally means the element is not
 // being rendered, though this might be overridden by the style sheets.
-// From https://html.spec.whatwg.org/multipage/rendering.html#being-rendered
+// From https://html.spec.whatwg.org/C/#being-rendered
 // static
 bool ElementInnerTextCollector::IsBeingRendered(const Node& node) {
   return node.GetLayoutObject();
diff --git a/third_party/blink/renderer/core/editing/ime/input_method_controller.cc b/third_party/blink/renderer/core/editing/ime/input_method_controller.cc
index 8cecdfb020f955..822e5a98795be6 100644
--- a/third_party/blink/renderer/core/editing/ime/input_method_controller.cc
+++ b/third_party/blink/renderer/core/editing/ime/input_method_controller.cc
@@ -321,7 +321,7 @@ int ComputeAutocapitalizeFlags(const Element* element) {
 
   // We set the autocapitalization flag corresponding to the "used
   // autocapitalization hint" for the focused element:
-  // https://html.spec.whatwg.org/multipage/interaction.html#used-autocapitalization-hint
+  // https://html.spec.whatwg.org/C/#used-autocapitalization-hint
   if (auto* input = ToHTMLInputElementOrNull(*html_element)) {
     const AtomicString& input_type = input->type();
     if (input_type == input_type_names::kEmail ||
diff --git a/third_party/blink/renderer/core/editing/iterators/text_iterator.cc b/third_party/blink/renderer/core/editing/iterators/text_iterator.cc
index bc0c5eb6e86fcc..53dfa1afcc829e 100644
--- a/third_party/blink/renderer/core/editing/iterators/text_iterator.cc
+++ b/third_party/blink/renderer/core/editing/iterators/text_iterator.cc
@@ -653,7 +653,7 @@ bool TextIteratorAlgorithm<Strategy>::ShouldEmitNewlineBeforeNode(
 }
 
 static bool ShouldEmitExtraNewlineForNode(const Node* node) {
-  // https://html.spec.whatwg.org/multipage/dom.html#the-innertext-idl-attribute
+  // https://html.spec.whatwg.org/C/#the-innertext-idl-attribute
   // Append two required linebreaks after a P element.
   LayoutObject* r = node->GetLayoutObject();
   if (!r || !r->IsBox())
diff --git a/third_party/blink/renderer/core/editing/serializers/markup_accumulator.cc b/third_party/blink/renderer/core/editing/serializers/markup_accumulator.cc
index ad4228e07f826f..2034cb82067105 100644
--- a/third_party/blink/renderer/core/editing/serializers/markup_accumulator.cc
+++ b/third_party/blink/renderer/core/editing/serializers/markup_accumulator.cc
@@ -127,7 +127,7 @@ bool MarkupAccumulator::ShouldIgnoreElement(const Element& element) const {
 }
 
 void MarkupAccumulator::AppendElement(const Element& element) {
-  // https://html.spec.whatwg.org/multipage/parsing.html#html-fragment-serialisation-algorithm
+  // https://html.spec.whatwg.org/C/#html-fragment-serialisation-algorithm
   RecordNamespaceInformation(element);
   AppendStartTagOpen(element);
 
diff --git a/third_party/blink/renderer/core/editing/serializers/markup_formatter.cc b/third_party/blink/renderer/core/editing/serializers/markup_formatter.cc
index 06a407b1bb8ff4..0d7aeec06277a8 100644
--- a/third_party/blink/renderer/core/editing/serializers/markup_formatter.cc
+++ b/third_party/blink/renderer/core/editing/serializers/markup_formatter.cc
@@ -314,7 +314,7 @@ void MarkupFormatter::AppendStartTagClose(StringBuilder& result,
 void MarkupFormatter::AppendAttributeAsHTML(StringBuilder& result,
                                             const Attribute& attribute,
                                             const String& value) {
-  // https://html.spec.whatwg.org/multipage/parsing.html#attribute's-serialised-name
+  // https://html.spec.whatwg.org/C/#attribute's-serialised-name
   QualifiedName prefixed_name = attribute.GetName();
   if (attribute.NamespaceURI() == xmlns_names::kNamespaceURI) {
     if (!attribute.Prefix() && attribute.LocalName() != g_xmlns_atom)
diff --git a/third_party/blink/renderer/core/events/drag_event.idl b/third_party/blink/renderer/core/events/drag_event.idl
index 57bfceca74cc3e..ba9e5838b56e64 100644
--- a/third_party/blink/renderer/core/events/drag_event.idl
+++ b/third_party/blink/renderer/core/events/drag_event.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/interaction.html#dragevent
+// https://html.spec.whatwg.org/C/#dragevent
 
 [
     Exposed=Window,
diff --git a/third_party/blink/renderer/core/events/drag_event_init.idl b/third_party/blink/renderer/core/events/drag_event_init.idl
index ccf5837cfcf0d5..91ec2b6627d3c7 100644
--- a/third_party/blink/renderer/core/events/drag_event_init.idl
+++ b/third_party/blink/renderer/core/events/drag_event_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/interaction.html#drageventinit
+// https://html.spec.whatwg.org/C/#drageventinit
 
 dictionary DragEventInit : MouseEventInit {
     [ImplementedAs=getDataTransfer] DataTransfer? dataTransfer;
diff --git a/third_party/blink/renderer/core/events/error_event.cc b/third_party/blink/renderer/core/events/error_event.cc
index 8421fe0011909d..635b06d063aa6d 100644
--- a/third_party/blink/renderer/core/events/error_event.cc
+++ b/third_party/blink/renderer/core/events/error_event.cc
@@ -41,7 +41,7 @@ namespace blink {
 ErrorEvent* ErrorEvent::CreateSanitizedError(ScriptState* script_state) {
   // "6. If script's muted errors is true, then set message to "Script error.",
   // urlString to the empty string, line and col to 0, and errorValue to null."
-  // https://html.spec.whatwg.org/multipage/webappapis.html#runtime-script-errors:muted-errors
+  // https://html.spec.whatwg.org/C/#runtime-script-errors:muted-errors
   DCHECK(script_state);
   return MakeGarbageCollected<ErrorEvent>(
       "Script error.", SourceLocation::Create(String(), 0, 0, nullptr),
diff --git a/third_party/blink/renderer/core/events/error_event.idl b/third_party/blink/renderer/core/events/error_event.idl
index 89d3b0cde09fd6..91f3e0d4a91b87 100644
--- a/third_party/blink/renderer/core/events/error_event.idl
+++ b/third_party/blink/renderer/core/events/error_event.idl
@@ -28,7 +28,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#the-errorevent-interface
+// https://html.spec.whatwg.org/C/#the-errorevent-interface
 
 [
     Constructor(DOMString type, optional ErrorEventInit eventInitDict),
diff --git a/third_party/blink/renderer/core/events/error_event_init.idl b/third_party/blink/renderer/core/events/error_event_init.idl
index 8a48d18381edab..29426b728a0bd4 100644
--- a/third_party/blink/renderer/core/events/error_event_init.idl
+++ b/third_party/blink/renderer/core/events/error_event_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#the-errorevent-interface
+// https://html.spec.whatwg.org/C/#the-errorevent-interface
 
 dictionary ErrorEventInit : EventInit {
     DOMString message;
diff --git a/third_party/blink/renderer/core/events/hash_change_event.idl b/third_party/blink/renderer/core/events/hash_change_event.idl
index d317e1b83446f0..8e38fdb76f7e65 100644
--- a/third_party/blink/renderer/core/events/hash_change_event.idl
+++ b/third_party/blink/renderer/core/events/hash_change_event.idl
@@ -17,7 +17,7 @@
  * Boston, MA 02110-1301, USA.
  */
 
-// https://html.spec.whatwg.org/multipage/browsers.html#the-hashchangeevent-interface
+// https://html.spec.whatwg.org/C/#the-hashchangeevent-interface
 
 [
     Constructor(DOMString type, optional HashChangeEventInit eventInitDict),
diff --git a/third_party/blink/renderer/core/events/hash_change_event_init.idl b/third_party/blink/renderer/core/events/hash_change_event_init.idl
index 495ba59a94920e..2be009e2f9aa77 100644
--- a/third_party/blink/renderer/core/events/hash_change_event_init.idl
+++ b/third_party/blink/renderer/core/events/hash_change_event_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/browsers.html#hashchangeevent
+// https://html.spec.whatwg.org/C/#hashchangeevent
 
 dictionary HashChangeEventInit : EventInit {
     DOMString oldURL;
diff --git a/third_party/blink/renderer/core/events/message_event.idl b/third_party/blink/renderer/core/events/message_event.idl
index 250ed2ce591371..e88852ecf25c08 100644
--- a/third_party/blink/renderer/core/events/message_event.idl
+++ b/third_party/blink/renderer/core/events/message_event.idl
@@ -25,7 +25,7 @@
  *
  */
 
-// https://html.spec.whatwg.org/multipage/comms.html#the-messageevent-interfaces
+// https://html.spec.whatwg.org/C/#the-messageevent-interfaces
 
 [
     Constructor(DOMString type, optional MessageEventInit eventInitDict),
diff --git a/third_party/blink/renderer/core/events/message_event_init.idl b/third_party/blink/renderer/core/events/message_event_init.idl
index d874b15b1ee7e5..2e4d36ef20ed85 100644
--- a/third_party/blink/renderer/core/events/message_event_init.idl
+++ b/third_party/blink/renderer/core/events/message_event_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/comms.html#the-messageevent-interfaces
+// https://html.spec.whatwg.org/C/#the-messageevent-interfaces
 
 dictionary MessageEventInit : EventInit {
     any data;
diff --git a/third_party/blink/renderer/core/events/mouse_event.idl b/third_party/blink/renderer/core/events/mouse_event.idl
index 3135644e42198c..c6728ebf416ff7 100644
--- a/third_party/blink/renderer/core/events/mouse_event.idl
+++ b/third_party/blink/renderer/core/events/mouse_event.idl
@@ -68,7 +68,7 @@
     [MeasureAs=MouseEventMovementY] readonly attribute long movementY;
 
     // Canvas Hit Regions
-    // https://html.spec.whatwg.org/multipage/scripting.html#MouseEvent-partial
+    // https://html.spec.whatwg.org/C/#MouseEvent-partial
     [RuntimeEnabled=CanvasHitRegion] readonly attribute DOMString? region;
 
     // Non-standard
diff --git a/third_party/blink/renderer/core/events/mouse_event_init.idl b/third_party/blink/renderer/core/events/mouse_event_init.idl
index 001c4ad5ae2b72..75c88c3f8782c9 100644
--- a/third_party/blink/renderer/core/events/mouse_event_init.idl
+++ b/third_party/blink/renderer/core/events/mouse_event_init.idl
@@ -19,6 +19,6 @@ dictionary MouseEventInit : EventModifierInit {
     long movementY = 0;
 
     // Canvas Hit Regions
-    // https://html.spec.whatwg.org/multipage/scripting.html#hit-regions:mouseeventinit
+    // https://html.spec.whatwg.org/C/#hit-regions:mouseeventinit
     DOMString? region = null;
 };
diff --git a/third_party/blink/renderer/core/events/page_transition_event.idl b/third_party/blink/renderer/core/events/page_transition_event.idl
index eb7e57cb18c368..9e85111400b661 100644
--- a/third_party/blink/renderer/core/events/page_transition_event.idl
+++ b/third_party/blink/renderer/core/events/page_transition_event.idl
@@ -23,7 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/browsers.html#the-pagetransitionevent-interface
+// https://html.spec.whatwg.org/C/#the-pagetransitionevent-interface
 
 [
     Constructor(DOMString type, optional PageTransitionEventInit eventInitDict),
diff --git a/third_party/blink/renderer/core/events/page_transition_event_init.idl b/third_party/blink/renderer/core/events/page_transition_event_init.idl
index 2571f082b28d43..024e3f0f0c96b5 100644
--- a/third_party/blink/renderer/core/events/page_transition_event_init.idl
+++ b/third_party/blink/renderer/core/events/page_transition_event_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/browsers.html#the-pagetransitionevent-interface
+// https://html.spec.whatwg.org/C/#the-pagetransitionevent-interface
 
 dictionary PageTransitionEventInit : EventInit {
     boolean persisted;
diff --git a/third_party/blink/renderer/core/events/pop_state_event.idl b/third_party/blink/renderer/core/events/pop_state_event.idl
index b632977a3eaf8e..874f5e5848a848 100644
--- a/third_party/blink/renderer/core/events/pop_state_event.idl
+++ b/third_party/blink/renderer/core/events/pop_state_event.idl
@@ -24,7 +24,7 @@
  *
  */
 
-// https://html.spec.whatwg.org/multipage/browsers.html#the-popstateevent-interface
+// https://html.spec.whatwg.org/C/#the-popstateevent-interface
 
 [
     Constructor(DOMString type, optional PopStateEventInit eventInitDict),
diff --git a/third_party/blink/renderer/core/events/pop_state_event_init.idl b/third_party/blink/renderer/core/events/pop_state_event_init.idl
index ce7ae0fe79066c..94e39788524200 100644
--- a/third_party/blink/renderer/core/events/pop_state_event_init.idl
+++ b/third_party/blink/renderer/core/events/pop_state_event_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/browsers.html#the-popstateevent-interface
+// https://html.spec.whatwg.org/C/#the-popstateevent-interface
 
 dictionary PopStateEventInit : EventInit {
     any state;
diff --git a/third_party/blink/renderer/core/execution_context/context_lifecycle_state_observer.h b/third_party/blink/renderer/core/execution_context/context_lifecycle_state_observer.h
index 86a067ec3340b4..2607f472bcd997 100644
--- a/third_party/blink/renderer/core/execution_context/context_lifecycle_state_observer.h
+++ b/third_party/blink/renderer/core/execution_context/context_lifecycle_state_observer.h
@@ -49,7 +49,7 @@ namespace blink {
 // observable effect on web-visible state, on should suspend that activity while
 // the page is paused by overriding ContextLifecycleStateChanged().
 //
-// https://html.spec.whatwg.org/multipage/webappapis.html#pause
+// https://html.spec.whatwg.org/C/#pause
 // https://wicg.github.io/page-lifecycle/spec.html
 class CORE_EXPORT ContextLifecycleStateObserver
     : public ContextLifecycleObserver {
diff --git a/third_party/blink/renderer/core/exported/web_shared_worker_impl.cc b/third_party/blink/renderer/core/exported/web_shared_worker_impl.cc
index 6b9c2a87a8d774..12f52f3ee7c9c3 100644
--- a/third_party/blink/renderer/core/exported/web_shared_worker_impl.cc
+++ b/third_party/blink/renderer/core/exported/web_shared_worker_impl.cc
@@ -208,7 +208,7 @@ void WebSharedWorkerImpl::Connect(MessagePortChannel web_channel) {
   DCHECK(IsMainThread());
   // The HTML spec requires to queue a connect event using the DOM manipulation
   // task source.
-  // https://html.spec.whatwg.org/multipage/workers.html#shared-workers-and-the-sharedworker-interface
+  // https://html.spec.whatwg.org/C/#shared-workers-and-the-sharedworker-interface
   PostCrossThreadTask(
       *GetWorkerThread()->GetTaskRunner(TaskType::kDOMManipulation), FROM_HERE,
       CrossThreadBind(&WebSharedWorkerImpl::ConnectTaskOnWorkerThread,
@@ -320,7 +320,7 @@ void WebSharedWorkerImpl::ContinueStartWorkerContext() {
 
   // Creates 'outside settings' used in the "Processing model" algorithm in the
   // HTML spec:
-  // https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+  // https://html.spec.whatwg.org/C/#worker-processing-model
   //
   // TODO(nhiroki): According to the spec, the 'outside settings' should
   // correspond to the Document that called 'new SharedWorker()'. However,
diff --git a/third_party/blink/renderer/core/frame/frame_owner.h b/third_party/blink/renderer/core/frame/frame_owner.h
index 2c5244703b8205..734fa1ef49e7e7 100644
--- a/third_party/blink/renderer/core/frame/frame_owner.h
+++ b/third_party/blink/renderer/core/frame/frame_owner.h
@@ -58,7 +58,7 @@ class CORE_EXPORT FrameOwner : public GarbageCollectedMixin {
 
   // Returns the 'name' content attribute value of the browsing context
   // container.
-  // https://html.spec.whatwg.org/multipage/browsers.html#browsing-context-container
+  // https://html.spec.whatwg.org/C/#browsing-context-container
   virtual AtomicString BrowsingContextContainerName() const = 0;
   virtual ScrollbarMode ScrollingMode() const = 0;
   virtual int MarginWidth() const = 0;
diff --git a/third_party/blink/renderer/core/frame/history.cc b/third_party/blink/renderer/core/frame/history.cc
index 32923260452e9f..b7753d118e1f3f 100644
--- a/third_party/blink/renderer/core/frame/history.cc
+++ b/third_party/blink/renderer/core/frame/history.cc
@@ -201,7 +201,7 @@ void History::go(ScriptState* script_state,
     // We intentionally call reload() for the current frame if delta is zero.
     // Otherwise, navigation happens on the root frame.
     // This behavior is designed in the following spec.
-    // https://html.spec.whatwg.org/multipage/browsers.html#dom-history-go
+    // https://html.spec.whatwg.org/C/#dom-history-go
     GetFrame()->Reload(WebFrameLoadType::kReload,
                        ClientRedirectPolicy::kClientRedirect);
   }
diff --git a/third_party/blink/renderer/core/frame/local_frame.cc b/third_party/blink/renderer/core/frame/local_frame.cc
index 8841d69ef19066..daf6c8f000dd30 100644
--- a/third_party/blink/renderer/core/frame/local_frame.cc
+++ b/third_party/blink/renderer/core/frame/local_frame.cc
@@ -902,7 +902,7 @@ bool LocalFrame::ShouldReuseDefaultView(
   // Since sandboxing turns the origin into an opaque origin it needs to also
   // be considered when deciding whether to reuse it.
   // Spec:
-  // https://html.spec.whatwg.org/multipage/browsing-the-web.html#initialise-the-document-object
+  // https://html.spec.whatwg.org/C/#initialise-the-document-object
   if (csp && (csp->GetSandboxMask() & kSandboxOrigin)) {
     return false;
   }
diff --git a/third_party/blink/renderer/core/frame/location.idl b/third_party/blink/renderer/core/frame/location.idl
index ba5f5683496c5e..ea47333ddb74f0 100644
--- a/third_party/blink/renderer/core/frame/location.idl
+++ b/third_party/blink/renderer/core/frame/location.idl
@@ -39,7 +39,7 @@
     // *existing* document at a different origin.
     // However, *reading* |href|, or accessing any component, is a security
     // problem, since that allows tracking navigation.
-    // https://html.spec.whatwg.org/multipage/browsers.html#crossoriginproperties-(-o-)
+    // https://html.spec.whatwg.org/C/#crossoriginproperties-(-o-)
     [CallWith=Isolate, CrossOrigin, RaisesException, Unforgeable] void replace(URLString url);
     [Unforgeable] void reload();
 
diff --git a/third_party/blink/renderer/core/frame/navigator_concurrent_hardware.idl b/third_party/blink/renderer/core/frame/navigator_concurrent_hardware.idl
index af79103d69b3aa..8976b5f87440b7 100644
--- a/third_party/blink/renderer/core/frame/navigator_concurrent_hardware.idl
+++ b/third_party/blink/renderer/core/frame/navigator_concurrent_hardware.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/workers.html#navigator.hardwareconcurrency
+// https://html.spec.whatwg.org/C/#navigator.hardwareconcurrency
 
 [
     NoInterfaceObject,
diff --git a/third_party/blink/renderer/core/frame/navigator_cookies.idl b/third_party/blink/renderer/core/frame/navigator_cookies.idl
index c77322a1428f9d..12b9b923089931 100644
--- a/third_party/blink/renderer/core/frame/navigator_cookies.idl
+++ b/third_party/blink/renderer/core/frame/navigator_cookies.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#cookies
+// https://html.spec.whatwg.org/C/#cookies
 
 [NoInterfaceObject]
 interface NavigatorCookies {
diff --git a/third_party/blink/renderer/core/frame/window.idl b/third_party/blink/renderer/core/frame/window.idl
index 51138a27c96804..e681b67bdb1358 100644
--- a/third_party/blink/renderer/core/frame/window.idl
+++ b/third_party/blink/renderer/core/frame/window.idl
@@ -93,7 +93,7 @@
     void queueMicrotask(VoidFunction callback);
 
     // AnimationFrameProvider mixin
-    // https://html.spec.whatwg.org/multipage/imagebitmap-and-animations.html#animation-frames
+    // https://html.spec.whatwg.org/C/#animation-frames
     [MeasureAs=UnprefixedRequestAnimationFrame] long requestAnimationFrame(FrameRequestCallback callback);
     void cancelAnimationFrame(long handle);
 
diff --git a/third_party/blink/renderer/core/frame/window_event_handlers.idl b/third_party/blink/renderer/core/frame/window_event_handlers.idl
index 2ee41eae597031..595cf78a3bdc2b 100644
--- a/third_party/blink/renderer/core/frame/window_event_handlers.idl
+++ b/third_party/blink/renderer/core/frame/window_event_handlers.idl
@@ -27,7 +27,7 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#windoweventhandlers
+// https://html.spec.whatwg.org/C/#windoweventhandlers
 
 [
     LegacyTreatAsPartialInterface,
diff --git a/third_party/blink/renderer/core/fullscreen/fullscreen.cc b/third_party/blink/renderer/core/fullscreen/fullscreen.cc
index 456df6999a771a..c8bbd0f186c15f 100644
--- a/third_party/blink/renderer/core/fullscreen/fullscreen.cc
+++ b/third_party/blink/renderer/core/fullscreen/fullscreen.cc
@@ -204,7 +204,7 @@ void Unfullscreen(Document& document) {
     Unfullscreen(*element);
 }
 
-// https://html.spec.whatwg.org/multipage/embedded-content.html#allowed-to-use
+// https://html.spec.whatwg.org/C/#allowed-to-use
 bool AllowedToUseFullscreen(const Document& document,
                             ReportOptions report_on_failure) {
   // To determine whether a Document object |document| is allowed to use the
diff --git a/third_party/blink/renderer/core/html/canvas/html_canvas_element.cc b/third_party/blink/renderer/core/html/canvas/html_canvas_element.cc
index 9c6ea82cb8c116..3e6826a9d9476c 100644
--- a/third_party/blink/renderer/core/html/canvas/html_canvas_element.cc
+++ b/third_party/blink/renderer/core/html/canvas/html_canvas_element.cc
@@ -1320,7 +1320,7 @@ bool HTMLCanvasElement::IsSupportedInteractiveCanvasFallback(
 
   // An element is a supported interactive canvas fallback element if it is one
   // of the following:
-  // https://html.spec.whatwg.org/multipage/scripting.html#supported-interactive-canvas-fallback-element
+  // https://html.spec.whatwg.org/C/#supported-interactive-canvas-fallback-element
 
   // An a element that represents a hyperlink and that does not have any img
   // descendants.
diff --git a/third_party/blink/renderer/core/html/canvas/html_canvas_element.idl b/third_party/blink/renderer/core/html/canvas/html_canvas_element.idl
index f62bc324fe90c6..52b74257efee0f 100644
--- a/third_party/blink/renderer/core/html/canvas/html_canvas_element.idl
+++ b/third_party/blink/renderer/core/html/canvas/html_canvas_element.idl
@@ -24,7 +24,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/canvas.html#the-canvas-element
+// https://html.spec.whatwg.org/C/#the-canvas-element
 [HTMLConstructor]
 interface HTMLCanvasElement : HTMLElement
 {
@@ -44,5 +44,5 @@ interface HTMLCanvasElement : HTMLElement
     [HighEntropy, RuntimeEnabled=CanvasColorManagement, MeasureAs=CanvasConvertToBlob, RaisesException, CallWith=ScriptState] Promise<Blob> convertToBlob(optional ImageEncodeOptions options);
 };
 
-// https://html.spec.whatwg.org/multipage/canvas.html#blobcallback
+// https://html.spec.whatwg.org/C/#blobcallback
 callback BlobCallback = void (Blob? blob);
diff --git a/third_party/blink/renderer/core/html/custom/ce_reactions_scope.h b/third_party/blink/renderer/core/html/custom/ce_reactions_scope.h
index 8578963d80b0b0..650d010c4b1978 100644
--- a/third_party/blink/renderer/core/html/custom/ce_reactions_scope.h
+++ b/third_party/blink/renderer/core/html/custom/ce_reactions_scope.h
@@ -16,7 +16,7 @@ namespace blink {
 class CustomElementReaction;
 class Element;
 
-// https://html.spec.whatwg.org/multipage/scripting.html#cereactions
+// https://html.spec.whatwg.org/C/#cereactions
 class CORE_EXPORT CEReactionsScope final {
   STACK_ALLOCATED();
 
diff --git a/third_party/blink/renderer/core/html/custom/custom_element.cc b/third_party/blink/renderer/core/html/custom/custom_element.cc
index 67956f5896f984..8e4c863689f4d9 100644
--- a/third_party/blink/renderer/core/html/custom/custom_element.cc
+++ b/third_party/blink/renderer/core/html/custom/custom_element.cc
@@ -198,7 +198,7 @@ HTMLElement* CustomElement::CreateFailedElement(Document& document,
   DCHECK(ShouldCreateCustomElement(tag_name));
 
   // "create an element for a token":
-  // https://html.spec.whatwg.org/multipage/syntax.html#create-an-element-for-the-token
+  // https://html.spec.whatwg.org/C/#create-an-element-for-the-token
 
   // 7. If this step throws an exception, let element be instead a new element
   // that implements HTMLUnknownElement, with no attributes, namespace set to
@@ -212,7 +212,7 @@ HTMLElement* CustomElement::CreateFailedElement(Document& document,
 
 void CustomElement::Enqueue(Element& element, CustomElementReaction& reaction) {
   // To enqueue an element on the appropriate element queue
-  // https://html.spec.whatwg.org/multipage/scripting.html#enqueue-an-element-on-the-appropriate-element-queue
+  // https://html.spec.whatwg.org/C/#enqueue-an-element-on-the-appropriate-element-queue
 
   // If the custom element reactions stack is not empty, then
   // Add element to the current element queue.
@@ -296,7 +296,7 @@ void CustomElement::EnqueueRestoreValueCallback(Element& element,
 void CustomElement::TryToUpgrade(Element& element,
                                  bool upgrade_invisible_elements) {
   // Try to upgrade an element
-  // https://html.spec.whatwg.org/multipage/scripting.html#concept-try-upgrade
+  // https://html.spec.whatwg.org/C/#concept-try-upgrade
 
   DCHECK_EQ(element.GetCustomElementState(), CustomElementState::kUndefined);
 
diff --git a/third_party/blink/renderer/core/html/custom/custom_element_definition.cc b/third_party/blink/renderer/core/html/custom/custom_element_definition.cc
index 62d852ab75031c..ef9e100950b60d 100644
--- a/third_party/blink/renderer/core/html/custom/custom_element_definition.cc
+++ b/third_party/blink/renderer/core/html/custom/custom_element_definition.cc
@@ -186,7 +186,7 @@ CustomElementDefinition::ConstructionStackScope::~ConstructionStackScope() {
   construction_stack_.pop_back();
 }
 
-// https://html.spec.whatwg.org/multipage/scripting.html#concept-upgrade-an-element
+// https://html.spec.whatwg.org/C/#concept-upgrade-an-element
 void CustomElementDefinition::Upgrade(Element& element) {
   DCHECK_EQ(element.GetCustomElementState(), CustomElementState::kUndefined);
 
@@ -287,7 +287,7 @@ void CustomElementDefinition::EnqueueAttributeChangedCallbackForAllAttributes(
     Element& element) {
   // Avoid synchronizing all attributes unless it is needed, while enqueing
   // callbacks "in order" as defined in the spec.
-  // https://html.spec.whatwg.org/multipage/scripting.html#concept-upgrade-an-element
+  // https://html.spec.whatwg.org/C/#concept-upgrade-an-element
   for (const AtomicString& name : observed_attributes_)
     element.SynchronizeAttribute(name);
   for (const auto& attribute : element.AttributesWithoutUpdate()) {
diff --git a/third_party/blink/renderer/core/html/custom/custom_element_definition_builder.h b/third_party/blink/renderer/core/html/custom/custom_element_definition_builder.h
index efc56d560273e0..eab6ef04d007f6 100644
--- a/third_party/blink/renderer/core/html/custom/custom_element_definition_builder.h
+++ b/third_party/blink/renderer/core/html/custom/custom_element_definition_builder.h
@@ -18,7 +18,7 @@ class CustomElementRegistry;
 
 // Implement CustomElementDefinitionBuilder to provide
 // technology-specific steps for CustomElementRegistry.define.
-// https://html.spec.whatwg.org/multipage/scripting.html#dom-customelementsregistry-define
+// https://html.spec.whatwg.org/C/#dom-customelementsregistry-define
 class CORE_EXPORT CustomElementDefinitionBuilder {
   STACK_ALLOCATED();
 
diff --git a/third_party/blink/renderer/core/html/custom/custom_element_descriptor.h b/third_party/blink/renderer/core/html/custom/custom_element_descriptor.h
index d24e368a0b9b41..59e781b49458fd 100644
--- a/third_party/blink/renderer/core/html/custom/custom_element_descriptor.h
+++ b/third_party/blink/renderer/core/html/custom/custom_element_descriptor.h
@@ -14,7 +14,7 @@
 namespace blink {
 
 // Describes what elements a custom element definition applies to.
-// https://html.spec.whatwg.org/multipage/scripting.html#custom-elements-core-concepts
+// https://html.spec.whatwg.org/C/#custom-elements-core-concepts
 //
 // There are two kinds of definitions:
 //
diff --git a/third_party/blink/renderer/core/html/custom/custom_element_reaction_factory.cc b/third_party/blink/renderer/core/html/custom/custom_element_reaction_factory.cc
index cfa12de8a0e753..1145659c508274 100644
--- a/third_party/blink/renderer/core/html/custom/custom_element_reaction_factory.cc
+++ b/third_party/blink/renderer/core/html/custom/custom_element_reaction_factory.cc
@@ -23,7 +23,7 @@ class CustomElementUpgradeReaction final : public CustomElementReaction {
   void Invoke(Element& element) override {
     // Don't call Upgrade() if it's already upgraded. Multiple upgrade reactions
     // could be enqueued because the state changes in step 10 of upgrades.
-    // https://html.spec.whatwg.org/multipage/scripting.html#upgrades
+    // https://html.spec.whatwg.org/C/#upgrades
     if (element.GetCustomElementState() == CustomElementState::kUndefined) {
       // Don't upgrade elements inside an invisible-static tree, unless it was
       // triggered by CustomElementRegistry::upgrade.
diff --git a/third_party/blink/renderer/core/html/custom/custom_element_reaction_queue.cc b/third_party/blink/renderer/core/html/custom/custom_element_reaction_queue.cc
index 386f02a9746212..0f7c3ea14c1d2e 100644
--- a/third_party/blink/renderer/core/html/custom/custom_element_reaction_queue.cc
+++ b/third_party/blink/renderer/core/html/custom/custom_element_reaction_queue.cc
@@ -35,7 +35,7 @@ void CustomElementReactionQueue::InvokeReactions(Element& element) {
   // Unlike V0CustomElementsCallbackQueue, reactions are always
   // inserted by steps which bump the global element queue. This
   // means we do not need queue "owner" guards.
-  // https://html.spec.whatwg.org/multipage/scripting.html#custom-element-reactions
+  // https://html.spec.whatwg.org/C/#custom-element-reactions
   Clear();
 }
 
diff --git a/third_party/blink/renderer/core/html/custom/custom_element_reaction_stack.cc b/third_party/blink/renderer/core/html/custom/custom_element_reaction_stack.cc
index da990e898311b4..990283baa647ac 100644
--- a/third_party/blink/renderer/core/html/custom/custom_element_reaction_stack.cc
+++ b/third_party/blink/renderer/core/html/custom/custom_element_reaction_stack.cc
@@ -81,7 +81,7 @@ void CustomElementReactionStack::Enqueue(Member<ElementQueue>& queue,
 void CustomElementReactionStack::EnqueueToBackupQueue(
     Element& element,
     CustomElementReaction& reaction) {
-  // https://html.spec.whatwg.org/multipage/scripting.html#backup-element-queue
+  // https://html.spec.whatwg.org/C/#backup-element-queue
 
   DCHECK(!CEReactionsScope::Current());
   DCHECK(stack_.IsEmpty());
diff --git a/third_party/blink/renderer/core/html/custom/custom_element_reaction_stack.h b/third_party/blink/renderer/core/html/custom/custom_element_reaction_stack.h
index b445589da29001..cac449fe709e01 100644
--- a/third_party/blink/renderer/core/html/custom/custom_element_reaction_stack.h
+++ b/third_party/blink/renderer/core/html/custom/custom_element_reaction_stack.h
@@ -16,7 +16,7 @@ class CustomElementReaction;
 class CustomElementReactionQueue;
 class Element;
 
-// https://html.spec.whatwg.org/multipage/scripting.html#custom-element-reactions
+// https://html.spec.whatwg.org/C/#custom-element-reactions
 class CORE_EXPORT CustomElementReactionStack final
     : public GarbageCollected<CustomElementReactionStack>,
       public NameClient {
diff --git a/third_party/blink/renderer/core/html/custom/custom_element_registry.cc b/third_party/blink/renderer/core/html/custom/custom_element_registry.cc
index 06817ada693a77..42546ebe2f7749 100644
--- a/third_party/blink/renderer/core/html/custom/custom_element_registry.cc
+++ b/third_party/blink/renderer/core/html/custom/custom_element_registry.cc
@@ -233,7 +233,7 @@ CustomElementDefinition* CustomElementRegistry::DefineInternal(
   return definition;
 }
 
-// https://html.spec.whatwg.org/multipage/scripting.html#dom-customelementsregistry-get
+// https://html.spec.whatwg.org/C/#dom-customelementsregistry-get
 ScriptValue CustomElementRegistry::get(const AtomicString& name) {
   CustomElementDefinition* definition = DefinitionForName(name);
   if (!definition) {
@@ -244,7 +244,7 @@ ScriptValue CustomElementRegistry::get(const AtomicString& name) {
   return definition->GetConstructorForScript();
 }
 
-// https://html.spec.whatwg.org/multipage/scripting.html#look-up-a-custom-element-definition
+// https://html.spec.whatwg.org/C/#look-up-a-custom-element-definition
 // At this point, what the spec calls 'is' is 'name' from desc
 CustomElementDefinition* CustomElementRegistry::DefinitionFor(
     const CustomElementDescriptor& desc) const {
@@ -310,7 +310,7 @@ void CustomElementRegistry::AddCandidate(Element& candidate) {
   set->insert(&candidate);
 }
 
-// https://html.spec.whatwg.org/multipage/scripting.html#dom-customelementsregistry-whendefined
+// https://html.spec.whatwg.org/C/#dom-customelementsregistry-whendefined
 ScriptPromise CustomElementRegistry::whenDefined(
     ScriptState* script_state,
     const AtomicString& name,
@@ -351,7 +351,7 @@ void CustomElementRegistry::CollectCandidates(
   sorter.Sorted(elements, document);
 }
 
-// https://html.spec.whatwg.org/multipage/custom-elements.html#dom-customelementregistry-upgrade
+// https://html.spec.whatwg.org/C/#dom-customelementregistry-upgrade
 void CustomElementRegistry::upgrade(Node* root) {
   DCHECK(root);
 
diff --git a/third_party/blink/renderer/core/html/document_all_name_collection.cc b/third_party/blink/renderer/core/html/document_all_name_collection.cc
index 777fd7fdfc9a8b..ad24083540a49a 100644
--- a/third_party/blink/renderer/core/html/document_all_name_collection.cc
+++ b/third_party/blink/renderer/core/html/document_all_name_collection.cc
@@ -12,7 +12,7 @@ DocumentAllNameCollection::DocumentAllNameCollection(ContainerNode& document,
     : HTMLNameCollection(document, kDocumentAllNamedItems, name) {}
 
 bool DocumentAllNameCollection::ElementMatches(const Element& element) const {
-  // https://html.spec.whatwg.org/multipage/common-dom-interfaces.html#all-named-elements
+  // https://html.spec.whatwg.org/C/#all-named-elements
   // Match below type of elements by name but any type of element by id.
   if (element.HasTagName(html_names::kATag) ||
       element.HasTagName(html_names::kButtonTag) ||
diff --git a/third_party/blink/renderer/core/html/document_name_collection.cc b/third_party/blink/renderer/core/html/document_name_collection.cc
index b18136f0118156..30b0781373ee61 100644
--- a/third_party/blink/renderer/core/html/document_name_collection.cc
+++ b/third_party/blink/renderer/core/html/document_name_collection.cc
@@ -13,7 +13,7 @@ DocumentNameCollection::DocumentNameCollection(ContainerNode& document,
                                                const AtomicString& name)
     : HTMLNameCollection(document, kDocumentNamedItems, name) {}
 
-// https://html.spec.whatwg.org/multipage/dom.html#dom-document-nameditem-filter
+// https://html.spec.whatwg.org/C/#dom-document-nameditem-filter
 bool DocumentNameCollection::ElementMatches(const HTMLElement& element) const {
   // Match images, forms, embeds, objects and iframes by name,
   // object by id, and images by id but only if they have
diff --git a/third_party/blink/renderer/core/html/forms/form_associated.h b/third_party/blink/renderer/core/html/forms/form_associated.h
index ee155b92cc90f6..9590a02c4f7215 100644
--- a/third_party/blink/renderer/core/html/forms/form_associated.h
+++ b/third_party/blink/renderer/core/html/forms/form_associated.h
@@ -10,7 +10,7 @@ namespace blink {
 class HTMLFormElement;
 
 // Contains code to associate form with a form associated element
-// https://html.spec.whatwg.org/multipage/forms.html#form-associated-element
+// https://html.spec.whatwg.org/C/#form-associated-element
 class FormAssociated {
  public:
   // HTMLFormElement can be null
diff --git a/third_party/blink/renderer/core/html/forms/form_data.cc b/third_party/blink/renderer/core/html/forms/form_data.cc
index 8a4627a0d49e48..190b3283a278ee 100644
--- a/third_party/blink/renderer/core/html/forms/form_data.cc
+++ b/third_party/blink/renderer/core/html/forms/form_data.cc
@@ -79,7 +79,7 @@ class FormDataIterationSource final
 };
 
 String Normalize(const String& input) {
-  // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#append-an-entry
+  // https://html.spec.whatwg.org/C/#append-an-entry
   return ReplaceUnmatchedSurrogates(NormalizeLineEndingsToCRLF(input));
 }
 
diff --git a/third_party/blink/renderer/core/html/forms/form_data_event.idl b/third_party/blink/renderer/core/html/forms/form_data_event.idl
index e507662757b6e4..f9ed68494792d0 100644
--- a/third_party/blink/renderer/core/html/forms/form_data_event.idl
+++ b/third_party/blink/renderer/core/html/forms/form_data_event.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#formdataevent
+// https://html.spec.whatwg.org/C/#formdataevent
 
 [
   Constructor(DOMString type, optional FormDataEventInit eventInitDict),
diff --git a/third_party/blink/renderer/core/html/forms/form_data_event_init.idl b/third_party/blink/renderer/core/html/forms/form_data_event_init.idl
index 3872929e83d2a2..ae477b979656c5 100644
--- a/third_party/blink/renderer/core/html/forms/form_data_event_init.idl
+++ b/third_party/blink/renderer/core/html/forms/form_data_event_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#formdataeventinit
+// https://html.spec.whatwg.org/C/#formdataeventinit
 
 dictionary FormDataEventInit : EventInit {
   required FormData formData;
diff --git a/third_party/blink/renderer/core/html/forms/html_form_control_element_with_state.cc b/third_party/blink/renderer/core/html/forms/html_form_control_element_with_state.cc
index b53738b094ffa5..4542c487d66200 100644
--- a/third_party/blink/renderer/core/html/forms/html_form_control_element_with_state.cc
+++ b/third_party/blink/renderer/core/html/forms/html_form_control_element_with_state.cc
@@ -130,7 +130,7 @@ String HTMLFormControlElementWithState::IDLExposedAutofillValue() const {
   // TODO(tkent): Share the code with autofill::FormStructure::
   // ParseFieldTypesFromAutocompleteAttributes().
 
-  // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#autofill-processing-model
+  // https://html.spec.whatwg.org/C/#autofill-processing-model
   // 1. If the element has no autocomplete attribute, then jump to the step
   // labeled default.
   const AtomicString& value = FastGetAttribute(html_names::kAutocompleteAttr);
diff --git a/third_party/blink/renderer/core/html/forms/html_form_control_element_with_state.h b/third_party/blink/renderer/core/html/forms/html_form_control_element_with_state.h
index 7ce8a725f82c98..ccaaa70fdbcc4b 100644
--- a/third_party/blink/renderer/core/html/forms/html_form_control_element_with_state.h
+++ b/third_party/blink/renderer/core/html/forms/html_form_control_element_with_state.h
@@ -60,7 +60,7 @@ class CORE_EXPORT HTMLFormControlElementWithState
  private:
   bool ShouldForceLegacyLayout() const final { return true; }
 
-  // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#autofill-anchor-mantle
+  // https://html.spec.whatwg.org/C/#autofill-anchor-mantle
   bool IsWearingAutofillAnchorMantle() const;
 };
 
diff --git a/third_party/blink/renderer/core/html/forms/html_form_element.cc b/third_party/blink/renderer/core/html/forms/html_form_element.cc
index 6a73a89661aca5..a5bfbfa69fea60 100644
--- a/third_party/blink/renderer/core/html/forms/html_form_element.cc
+++ b/third_party/blink/renderer/core/html/forms/html_form_element.cc
@@ -354,7 +354,7 @@ void HTMLFormElement::Submit(Event* event,
   if (!view || !frame || !frame->GetPage())
     return;
 
-  // https://html.spec.whatwg.org/multipage/forms.html#form-submission-algorithm
+  // https://html.spec.whatwg.org/C/#form-submission-algorithm
   // 2. If form document is not connected, has no associated browsing context,
   // or its active sandboxing flag set has its sandboxed forms browsing
   // context flag set, then abort these steps without doing anything.
diff --git a/third_party/blink/renderer/core/html/forms/html_form_element.h b/third_party/blink/renderer/core/html/forms/html_form_element.h
index 48e8bd0b551544..23befd3076e9d9 100644
--- a/third_party/blink/renderer/core/html/forms/html_form_element.h
+++ b/third_party/blink/renderer/core/html/forms/html_form_element.h
@@ -92,7 +92,7 @@ class CORE_EXPORT HTMLFormElement final : public HTMLElement {
   void setMethod(const AtomicString&);
 
   // Find the 'default button.'
-  // https://html.spec.whatwg.org/multipage/forms.html#default-button
+  // https://html.spec.whatwg.org/C/#default-button
   HTMLFormControlElement* FindDefaultButton() const;
 
   bool checkValidity();
@@ -111,7 +111,7 @@ class CORE_EXPORT HTMLFormElement final : public HTMLElement {
   void InvalidateDefaultButtonStyle() const;
 
   // 'construct the entry list'
-  // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#constructing-the-form-data-set
+  // https://html.spec.whatwg.org/C/#constructing-the-form-data-set
   // Returns nullptr if this form is already running this function.
   FormData* ConstructEntryList(HTMLFormControlElement* submit_button,
                                const WTF::TextEncoding& encoding);
@@ -165,7 +165,7 @@ class CORE_EXPORT HTMLFormElement final : public HTMLElement {
   // Do not access image_elements_ directly. Use ImageElements() instead.
   HeapVector<Member<HTMLImageElement>> image_elements_;
 
-  // https://html.spec.whatwg.org/multipage/forms.html#planned-navigation
+  // https://html.spec.whatwg.org/C/#planned-navigation
   // Unlike the specification, we use this only for web-exposed submit()
   // function in 'submit' event handler.
   Member<FormSubmission> planned_navigation_;
diff --git a/third_party/blink/renderer/core/html/forms/html_input_element.cc b/third_party/blink/renderer/core/html/forms/html_input_element.cc
index 2a29a0ec6dbf92..e197fd7f6e2cf0 100644
--- a/third_party/blink/renderer/core/html/forms/html_input_element.cc
+++ b/third_party/blink/renderer/core/html/forms/html_input_element.cc
@@ -461,7 +461,7 @@ void HTMLInputElement::UpdateType() {
 
   ValueMode new_value_mode = input_type_->GetValueMode();
 
-  // https://html.spec.whatwg.org/multipage/forms.html#input-type-change
+  // https://html.spec.whatwg.org/C/#input-type-change
   //
   // 1. If the previous state of the element's type attribute put the value IDL
   // attribute in the value mode, and the element's value is not the empty
diff --git a/third_party/blink/renderer/core/html/forms/html_input_element.h b/third_party/blink/renderer/core/html/forms/html_input_element.h
index 43e0f412b34914..ddcb54e6640922 100644
--- a/third_party/blink/renderer/core/html/forms/html_input_element.h
+++ b/third_party/blink/renderer/core/html/forms/html_input_element.h
@@ -409,11 +409,11 @@ class CORE_EXPORT HTMLInputElement
   // The value string in |value| value mode.
   String non_attribute_value_;
   unsigned size_;
-  // https://html.spec.whatwg.org/multipage/forms.html#concept-input-value-dirty-flag
+  // https://html.spec.whatwg.org/C/#concept-input-value-dirty-flag
   unsigned has_dirty_value_ : 1;
-  // https://html.spec.whatwg.org/multipage/forms.html#concept-fe-checked
+  // https://html.spec.whatwg.org/C/#concept-fe-checked
   unsigned is_checked_ : 1;
-  // https://html.spec.whatwg.org/multipage/forms.html#concept-input-checked-dirty-flag
+  // https://html.spec.whatwg.org/C/#concept-input-checked-dirty-flag
   unsigned dirty_checkedness_ : 1;
   unsigned is_indeterminate_ : 1;
   unsigned is_activated_submit_ : 1;
diff --git a/third_party/blink/renderer/core/html/forms/html_label_element.cc b/third_party/blink/renderer/core/html/forms/html_label_element.cc
index 906743e4673113..0c28691703e012 100644
--- a/third_party/blink/renderer/core/html/forms/html_label_element.cc
+++ b/third_party/blink/renderer/core/html/forms/html_label_element.cc
@@ -52,7 +52,7 @@ HTMLLabelElement* HTMLLabelElement::Create(Document& document) {
 }
 
 HTMLElement* HTMLLabelElement::control() const {
-  // https://html.spec.whatwg.org/multipage/forms.html#labeled-control
+  // https://html.spec.whatwg.org/C/#labeled-control
   const AtomicString& control_id = getAttribute(kForAttr);
   if (control_id.IsNull()) {
     // "If the for attribute is not specified, but the label element has a
diff --git a/third_party/blink/renderer/core/html/forms/html_option_element.h b/third_party/blink/renderer/core/html/forms/html_option_element.h
index fb3c45f81dc1b4..a4432a9d485540 100644
--- a/third_party/blink/renderer/core/html/forms/html_option_element.h
+++ b/third_party/blink/renderer/core/html/forms/html_option_element.h
@@ -111,10 +111,10 @@ class CORE_EXPORT HTMLOptionElement final : public HTMLElement {
   void UpdateLabel();
 
   // Represents 'selectedness'.
-  // https://html.spec.whatwg.org/multipage/forms.html#concept-option-selectedness
+  // https://html.spec.whatwg.org/C/#concept-option-selectedness
   bool is_selected_;
   // Represents 'dirtiness'.
-  // https://html.spec.whatwg.org/multipage/forms.html#concept-option-dirtiness
+  // https://html.spec.whatwg.org/C/#concept-option-dirtiness
   bool is_dirty_ = false;
 };
 
diff --git a/third_party/blink/renderer/core/html/forms/html_select_element.cc b/third_party/blink/renderer/core/html/forms/html_select_element.cc
index 43680a40b06ef8..29fad5a85e8ea6 100644
--- a/third_party/blink/renderer/core/html/forms/html_select_element.cc
+++ b/third_party/blink/renderer/core/html/forms/html_select_element.cc
@@ -793,7 +793,7 @@ void HTMLSelectElement::RecalcListItems() const {
 }
 
 void HTMLSelectElement::ResetToDefaultSelection(ResetReason reason) {
-  // https://html.spec.whatwg.org/multipage/forms.html#ask-for-a-reset
+  // https://html.spec.whatwg.org/C/#ask-for-a-reset
   if (IsMultiple())
     return;
   HTMLOptionElement* first_enabled_option = nullptr;
diff --git a/third_party/blink/renderer/core/html/forms/input_type.cc b/third_party/blink/renderer/core/html/forms/input_type.cc
index 340fe9a184a18c..5512651105be72 100644
--- a/third_party/blink/renderer/core/html/forms/input_type.cc
+++ b/third_party/blink/renderer/core/html/forms/input_type.cc
@@ -354,7 +354,7 @@ std::pair<String, String> InputType::ValidationMessage(
     return std::make_pair(TypeMismatchText(), g_empty_string);
 
   if (PatternMismatch(value)) {
-    // https://html.spec.whatwg.org/multipage/forms.html#attr-input-pattern
+    // https://html.spec.whatwg.org/C/#attr-input-pattern
     //   When an input element has a pattern attribute specified, authors
     //   should include a title attribute to give a description of the
     //   pattern. User agents may use the contents of this attribute, if it
@@ -675,7 +675,7 @@ void InputType::ApplyStep(const Decimal& current,
                           AnyStepHandling any_step_handling,
                           TextFieldEventBehavior event_behavior,
                           ExceptionState& exception_state) {
-  // https://html.spec.whatwg.org/multipage/forms.html#dom-input-stepup
+  // https://html.spec.whatwg.org/C/#dom-input-stepup
 
   StepRange step_range(CreateStepRange(any_step_handling));
   // 2. If the element has no allowed value step, then throw an
diff --git a/third_party/blink/renderer/core/html/forms/input_type.h b/third_party/blink/renderer/core/html/forms/input_type.h
index 22475ab265724d..1108f593dd27a4 100644
--- a/third_party/blink/renderer/core/html/forms/input_type.h
+++ b/third_party/blink/renderer/core/html/forms/input_type.h
@@ -91,7 +91,7 @@ class CORE_EXPORT InputType : public GarbageCollectedFinalized<InputType> {
   // is missing.
   virtual String DefaultLabel() const;
 
-  // https://html.spec.whatwg.org/multipage/forms.html#dom-input-value
+  // https://html.spec.whatwg.org/C/#dom-input-value
   enum class ValueMode { kValue, kDefault, kDefaultOn, kFilename };
   virtual ValueMode GetValueMode() const = 0;
 
diff --git a/third_party/blink/renderer/core/html/forms/listed_element.h b/third_party/blink/renderer/core/html/forms/listed_element.h
index d79eab14770c34..62c5a78f63e67a 100644
--- a/third_party/blink/renderer/core/html/forms/listed_element.h
+++ b/third_party/blink/renderer/core/html/forms/listed_element.h
@@ -44,7 +44,7 @@ class Node;
 class ValidationMessageClient;
 class ValidityState;
 
-// https://html.spec.whatwg.org/multipage/forms.html#category-listed
+// https://html.spec.whatwg.org/C/#category-listed
 class CORE_EXPORT ListedElement : public GarbageCollectedMixin {
  public:
   virtual ~ListedElement();
@@ -118,9 +118,9 @@ class CORE_EXPORT ListedElement : public GarbageCollectedMixin {
   bool IsValidElement();
   // Returns true if
   //  - this is not a candidate for constraint validation, or
-  //    https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#candidate-for-constraint-validation
+  //    https://html.spec.whatwg.org/C/#candidate-for-constraint-validation
   //  - this satisfies its constraints
-  //    https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#concept-fv-valid
+  //    https://html.spec.whatwg.org/C/#concept-fv-valid
   bool IsNotCandidateOrValid();
 
   // This must be called when a validation constraint or control value is
@@ -144,7 +144,7 @@ class CORE_EXPORT ListedElement : public GarbageCollectedMixin {
   // This is for HTMLFieldSetElement class.
   void AncestorDisabledStateWasChanged();
 
-  // https://html.spec.whatwg.org/multipage/semantics-other.html#concept-element-disabled
+  // https://html.spec.whatwg.org/C/#concept-element-disabled
   bool IsActuallyDisabled() const;
 
   // Returns a static value of class-level support of the state restore
diff --git a/third_party/blink/renderer/core/html/forms/range_input_type.cc b/third_party/blink/renderer/core/html/forms/range_input_type.cc
index 34d73082e5cef3..8766fc24011596 100644
--- a/third_party/blink/renderer/core/html/forms/range_input_type.cc
+++ b/third_party/blink/renderer/core/html/forms/range_input_type.cc
@@ -144,7 +144,7 @@ StepRange RangeInputType::CreateStepRange(
                            GetElement().FastGetAttribute(kStepAttr));
   // Range type always has range limitations because it has default
   // minimum/maximum.
-  // https://html.spec.whatwg.org/multipage/forms.html#range-state-(type=range):concept-input-min-default
+  // https://html.spec.whatwg.org/C/#range-state-(type=range):concept-input-min-default
   const bool kHasRangeLimitations = true;
   return StepRange(step_base, minimum, maximum, kHasRangeLimitations, step,
                    step_description);
diff --git a/third_party/blink/renderer/core/html/forms/step_range.h b/third_party/blink/renderer/core/html/forms/step_range.h
index 9bd9daad9467bf..b62c182a00d75a 100644
--- a/third_party/blink/renderer/core/html/forms/step_range.h
+++ b/third_party/blink/renderer/core/html/forms/step_range.h
@@ -83,7 +83,7 @@ class CORE_EXPORT StepRange {
   bool HasStep() const { return has_step_; }
   Decimal Maximum() const { return maximum_; }
   Decimal Minimum() const { return minimum_; }
-  // https://html.spec.whatwg.org/multipage/forms.html#have-range-limitations
+  // https://html.spec.whatwg.org/C/#have-range-limitations
   bool HasRangeLimitations() const { return has_range_limitations_; }
   static Decimal ParseStep(AnyStepHandling,
                            const StepDescription&,
diff --git a/third_party/blink/renderer/core/html/html_base_element.cc b/third_party/blink/renderer/core/html/html_base_element.cc
index 24a433a8c30678..607a66765da91c 100644
--- a/third_party/blink/renderer/core/html/html_base_element.cc
+++ b/third_party/blink/renderer/core/html/html_base_element.cc
@@ -81,7 +81,7 @@ KURL HTMLBaseElement::href() const {
   // relative to the document's base URL; base elements like this one can be
   // used to set that base URL. Thus we need to resolve relative to the
   // document's fallback base URL and ignore the base URL.
-  // https://html.spec.whatwg.org/multipage/semantics.html#dom-base-href
+  // https://html.spec.whatwg.org/C/#dom-base-href
 
   const AtomicString& attribute_value = FastGetAttribute(kHrefAttr);
   if (attribute_value.IsNull())
diff --git a/third_party/blink/renderer/core/html/html_collection.cc b/third_party/blink/renderer/core/html/html_collection.cc
index b8692228cf5b14..0abc7e9389de8f 100644
--- a/third_party/blink/renderer/core/html/html_collection.cc
+++ b/third_party/blink/renderer/core/html/html_collection.cc
@@ -336,7 +336,7 @@ Element* HTMLCollection::VirtualItemAfter(Element*) const {
   return nullptr;
 }
 
-// https://html.spec.whatwg.org/multipage/infrastructure.html#all-named-elements
+// https://html.spec.whatwg.org/C/#all-named-elements
 // The document.all collection returns only certain types of elements by name,
 // although it returns any type of element by id.
 static inline bool NameShouldBeVisibleInDocumentAll(
diff --git a/third_party/blink/renderer/core/html/html_data_element.idl b/third_party/blink/renderer/core/html/html_data_element.idl
index 6f65099d36eff5..3006a5c5bf678e 100644
--- a/third_party/blink/renderer/core/html/html_data_element.idl
+++ b/third_party/blink/renderer/core/html/html_data_element.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/text-level-semantics.html#the-data-element
+// https://html.spec.whatwg.org/C/#the-data-element
 
 [HTMLConstructor]
 interface HTMLDataElement : HTMLElement {
diff --git a/third_party/blink/renderer/core/html/html_dimension.cc b/third_party/blink/renderer/core/html/html_dimension.cc
index e1b0caf99ff005..a60bb1425dc3af 100644
--- a/third_party/blink/renderer/core/html/html_dimension.cc
+++ b/third_party/blink/renderer/core/html/html_dimension.cc
@@ -187,7 +187,7 @@ static bool ParseDimensionValue(const CharacterType* current,
   return true;
 }
 
-// https://html.spec.whatwg.org/multipage/infrastructure.html#rules-for-parsing-dimension-values
+// https://html.spec.whatwg.org/C/#rules-for-parsing-dimension-values
 bool ParseDimensionValue(const String& input, HTMLDimension& dimension) {
   if (input.IsEmpty())
     return false;
diff --git a/third_party/blink/renderer/core/html/html_element.cc b/third_party/blink/renderer/core/html/html_element.cc
index f9a5028e6dee92..f65eace11cdb32 100644
--- a/third_party/blink/renderer/core/html/html_element.cc
+++ b/third_party/blink/renderer/core/html/html_element.cc
@@ -1008,7 +1008,7 @@ void HTMLElement::ChildrenChanged(const ChildrenChange& change) {
 
 bool HTMLElement::HasDirectionAuto() const {
   // <bdi> defaults to dir="auto"
-  // https://html.spec.whatwg.org/multipage/semantics.html#the-bdi-element
+  // https://html.spec.whatwg.org/C/#the-bdi-element
   const AtomicString& direction = FastGetAttribute(kDirAttr);
   return (IsHTMLBDIElement(*this) && direction == g_null_atom) ||
          DeprecatedEqualIgnoringCase(direction, "auto");
diff --git a/third_party/blink/renderer/core/html/html_element.h b/third_party/blink/renderer/core/html/html_element.h
index 7ea5752af217ee..69b69408d9372b 100644
--- a/third_party/blink/renderer/core/html/html_element.h
+++ b/third_party/blink/renderer/core/html/html_element.h
@@ -109,7 +109,7 @@ class CORE_EXPORT HTMLElement : public Element {
   virtual bool IsHTMLUnknownElement() const { return false; }
   virtual bool IsPluginElement() const { return false; }
 
-  // https://html.spec.whatwg.org/multipage/forms.html#category-label
+  // https://html.spec.whatwg.org/C/#category-label
   virtual bool IsLabelable() const;
   // |labels| IDL attribute implementation for IsLabelable()==true elements.
   LabelsNodeList* labels();
diff --git a/third_party/blink/renderer/core/html/html_embed_element.cc b/third_party/blink/renderer/core/html/html_embed_element.cc
index ced7efacb6b26c..b3d614d5af4e8c 100644
--- a/third_party/blink/renderer/core/html/html_embed_element.cc
+++ b/third_party/blink/renderer/core/html/html_embed_element.cc
@@ -181,7 +181,7 @@ bool HTMLEmbedElement::LayoutObjectIsNeeded(const ComputedStyle& style) const {
   if (IsImageType())
     return HTMLPlugInElement::LayoutObjectIsNeeded(style);
 
-  // https://html.spec.whatwg.org/multipage/embedded-content.html#the-embed-element
+  // https://html.spec.whatwg.org/C/#the-embed-element
   // While any of the following conditions are occurring, any plugin
   // instantiated for the element must be removed, and the embed element
   // represents nothing:
diff --git a/third_party/blink/renderer/core/html/html_image_element.h b/third_party/blink/renderer/core/html/html_image_element.h
index e8769a36dff413..9cf024e5396640 100644
--- a/third_party/blink/renderer/core/html/html_image_element.h
+++ b/third_party/blink/renderer/core/html/html_image_element.h
@@ -181,7 +181,7 @@ class CORE_EXPORT HTMLImageElement final
 
  protected:
   // Controls how an image element appears in the layout. See:
-  // https://html.spec.whatwg.org/multipage/embedded-content.html#image-request
+  // https://html.spec.whatwg.org/C/#image-request
   enum class LayoutDisposition : uint8_t {
     // Displayed as a partially or completely loaded image. Corresponds to the
     // `current request` state being: `unavailable`, `partially available`, or
diff --git a/third_party/blink/renderer/core/html/html_image_fallback_helper.cc b/third_party/blink/renderer/core/html/html_image_fallback_helper.cc
index ac14855c989fd9..d55f46f4d8c0ad 100644
--- a/third_party/blink/renderer/core/html/html_image_fallback_helper.cc
+++ b/third_party/blink/renderer/core/html/html_image_fallback_helper.cc
@@ -116,7 +116,7 @@ scoped_refptr<ComputedStyle> HTMLImageFallbackHelper::CustomStyleForAltText(
       image_has_intrinsic_dimensions &&
       (element.GetDocument().InQuirksMode() || image_has_no_alt_attribute);
   if (treat_as_replaced) {
-    // https://html.spec.whatwg.org/multipage/rendering.html#images-3:
+    // https://html.spec.whatwg.org/C/#images-3:
     // "If the element does not represent an image, but the element already has
     // intrinsic dimensions (e.g. from the dimension attributes or CSS rules),
     // and either: the user agent has reason to believe that the image will
diff --git a/third_party/blink/renderer/core/html/html_object_element.h b/third_party/blink/renderer/core/html/html_object_element.h
index 3ae37a65977dda..d04d10d02a069b 100644
--- a/third_party/blink/renderer/core/html/html_object_element.h
+++ b/third_party/blink/renderer/core/html/html_object_element.h
@@ -36,7 +36,7 @@ class HTMLFormElement;
 // Inheritance of ListedElement was used for NPAPI form association, but
 // is still kept here so that legacy APIs such as form attribute can keep
 // working according to the spec.  See:
-// https://html.spec.whatwg.org/multipage/embedded-content.html#the-object-element
+// https://html.spec.whatwg.org/C/#the-object-element
 class CORE_EXPORT HTMLObjectElement final : public HTMLPlugInElement,
                                             public ListedElement,
                                             public FormAssociated {
diff --git a/third_party/blink/renderer/core/html/html_table_row_element_test.cc b/third_party/blink/renderer/core/html/html_table_row_element_test.cc
index 5ba4120c5375ac..cdf795e72ae3cc 100644
--- a/third_party/blink/renderer/core/html/html_table_row_element_test.cc
+++ b/third_party/blink/renderer/core/html/html_table_row_element_test.cc
@@ -12,7 +12,7 @@
 namespace blink {
 
 // rowIndex
-// https://html.spec.whatwg.org/multipage/tables.html#dom-tr-rowindex
+// https://html.spec.whatwg.org/C/#dom-tr-rowindex
 
 TEST(HTMLTableRowElementTest, rowIndex_notInTable) {
   Document* document = Document::CreateForTest();
diff --git a/third_party/blink/renderer/core/html/html_template_element.cc b/third_party/blink/renderer/core/html/html_template_element.cc
index 50f7864a0e4993..06b8ea39602f96 100644
--- a/third_party/blink/renderer/core/html/html_template_element.cc
+++ b/third_party/blink/renderer/core/html/html_template_element.cc
@@ -57,7 +57,7 @@ DocumentFragment* HTMLTemplateElement::content() const {
   return content_.Get();
 }
 
-// https://html.spec.whatwg.org/multipage/scripting.html#the-template-element:concept-node-clone-ext
+// https://html.spec.whatwg.org/C/#the-template-element:concept-node-clone-ext
 void HTMLTemplateElement::CloneNonAttributePropertiesFrom(
     const Element& source,
     CloneChildrenFlag flag) {
diff --git a/third_party/blink/renderer/core/html/html_time_element.idl b/third_party/blink/renderer/core/html/html_time_element.idl
index 48677ffe779111..3f6e0c95ac8367 100644
--- a/third_party/blink/renderer/core/html/html_time_element.idl
+++ b/third_party/blink/renderer/core/html/html_time_element.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/text-level-semantics.html#the-time-element
+// https://html.spec.whatwg.org/C/#the-time-element
 
 [HTMLConstructor]
 interface HTMLTimeElement : HTMLElement {
diff --git a/third_party/blink/renderer/core/html/image_document.cc b/third_party/blink/renderer/core/html/image_document.cc
index 0638e3e60565b2..f68b9efe2d7236 100644
--- a/third_party/blink/renderer/core/html/image_document.cc
+++ b/third_party/blink/renderer/core/html/image_document.cc
@@ -262,7 +262,7 @@ void ImageDocument::CreateDocumentStructure() {
     // Adding a UA shadow root here is because the container <div> should be
     // hidden so that only the <img> element should be visible in <body>,
     // according to the spec:
-    // https://html.spec.whatwg.org/multipage/browsing-the-web.html#read-media
+    // https://html.spec.whatwg.org/C/#read-media
     ShadowRoot& shadow_root = body->EnsureUserAgentShadowRoot();
     shadow_root.AppendChild(div_element_);
   } else {
diff --git a/third_party/blink/renderer/core/html/list_item_ordinal.h b/third_party/blink/renderer/core/html/list_item_ordinal.h
index 2de33545c842c4..c830556f3bd08d 100644
--- a/third_party/blink/renderer/core/html/list_item_ordinal.h
+++ b/third_party/blink/renderer/core/html/list_item_ordinal.h
@@ -39,7 +39,7 @@ class LayoutObject;
 class Node;
 
 // Represents an "ordinal value" and its related algorithms:
-// https://html.spec.whatwg.org/multipage/grouping-content.html#ordinal-value
+// https://html.spec.whatwg.org/C/#ordinal-value
 //
 // The ordinal value is determined by the DOM tree order. However, since any
 // elements with 'display: list-item' can be list items, the layout tree
diff --git a/third_party/blink/renderer/core/html/media/html_media_element.cc b/third_party/blink/renderer/core/html/media/html_media_element.cc
index 8f3f91e7ec446a..eecab415f2c162 100644
--- a/third_party/blink/renderer/core/html/media/html_media_element.cc
+++ b/third_party/blink/renderer/core/html/media/html_media_element.cc
@@ -2905,7 +2905,7 @@ TextTrack* HTMLMediaElement::addTextTrack(const AtomicString& kind,
                                           const AtomicString& label,
                                           const AtomicString& language,
                                           ExceptionState& exception_state) {
-  // https://html.spec.whatwg.org/multipage/embedded-content.html#dom-media-addtexttrack
+  // https://html.spec.whatwg.org/C/#dom-media-addtexttrack
 
   // The addTextTrack(kind, label, language) method of media elements, when
   // invoked, must run the following steps:
diff --git a/third_party/blink/renderer/core/html/media/html_media_element.h b/third_party/blink/renderer/core/html/media/html_media_element.h
index 75753e3eced5f7..6880740312c3e3 100644
--- a/third_party/blink/renderer/core/html/media/html_media_element.h
+++ b/third_party/blink/renderer/core/html/media/html_media_element.h
@@ -515,7 +515,7 @@ class CORE_EXPORT HTMLMediaElement
   // Generally the presence of the loop attribute should be considered to mean
   // playback has not "ended", as "ended" and "looping" are mutually exclusive.
   // See
-  // https://html.spec.whatwg.org/multipage/embedded-content.html#ended-playback
+  // https://html.spec.whatwg.org/C/#ended-playback
   enum class LoopCondition { kIncluded, kIgnored };
   bool EndedPlayback(LoopCondition = LoopCondition::kIncluded) const;
 
diff --git a/third_party/blink/renderer/core/html/parser/html_construction_site.cc b/third_party/blink/renderer/core/html/parser/html_construction_site.cc
index 469e175a8d4d22..98285a5ddb63ae 100644
--- a/third_party/blink/renderer/core/html/parser/html_construction_site.cc
+++ b/third_party/blink/renderer/core/html/parser/html_construction_site.cc
@@ -871,7 +871,7 @@ CustomElementDefinition* HTMLConstructionSite::LookUpCustomElementDefinition(
 }
 
 // "create an element for a token"
-// https://html.spec.whatwg.org/multipage/syntax.html#create-an-element-for-the-token
+// https://html.spec.whatwg.org/C/#create-an-element-for-the-token
 Element* HTMLConstructionSite::CreateElement(
     AtomicHTMLToken* token,
     const AtomicString& namespace_uri) {
diff --git a/third_party/blink/renderer/core/html/parser/html_construction_site.h b/third_party/blink/renderer/core/html/parser/html_construction_site.h
index fe5e571b786be6..6a00a155bf38b3 100644
--- a/third_party/blink/renderer/core/html/parser/html_construction_site.h
+++ b/third_party/blink/renderer/core/html/parser/html_construction_site.h
@@ -275,9 +275,9 @@ class HTMLConstructionSite final {
   // and a Document in all other cases.
   Member<ContainerNode> attachment_root_;
 
-  // https://html.spec.whatwg.org/multipage/syntax.html#head-element-pointer
+  // https://html.spec.whatwg.org/C/#head-element-pointer
   Member<HTMLStackItem> head_;
-  // https://html.spec.whatwg.org/multipage/syntax.html#form-element-pointer
+  // https://html.spec.whatwg.org/C/#form-element-pointer
   Member<HTMLFormElement> form_;
   mutable HTMLElementStack open_elements_;
   mutable HTMLFormattingElementList active_formatting_elements_;
diff --git a/third_party/blink/renderer/core/html/parser/html_parser_idioms.cc b/third_party/blink/renderer/core/html/parser/html_parser_idioms.cc
index 4200c56f7d17e7..c870dda4b497f6 100644
--- a/third_party/blink/renderer/core/html/parser/html_parser_idioms.cc
+++ b/third_party/blink/renderer/core/html/parser/html_parser_idioms.cc
@@ -199,12 +199,12 @@ static WTF::NumberParsingResult ParseHTMLNonNegativeIntegerInternal(
     const CharacterType* end,
     unsigned& value) {
   // This function is an implementation of the following algorithm:
-  // https://html.spec.whatwg.org/multipage/infrastructure.html#rules-for-parsing-non-negative-integers
+  // https://html.spec.whatwg.org/C/#rules-for-parsing-non-negative-integers
   // However, in order to support integers >= 2^31, we fold [1] into this.
   // 'Step N' in the following comments refers to [1].
   //
   // [1]
-  // https://html.spec.whatwg.org/multipage/infrastructure.html#rules-for-parsing-integers
+  // https://html.spec.whatwg.org/C/#rules-for-parsing-integers
 
   // Step 4: Skip whitespace.
   SkipWhile<CharacterType, IsHTMLSpace<CharacterType>>(position, end);
@@ -241,7 +241,7 @@ static WTF::NumberParsingResult ParseHTMLNonNegativeIntegerInternal(
   return ParseHTMLNonNegativeIntegerInternal(start, start + length, value);
 }
 
-// https://html.spec.whatwg.org/multipage/infrastructure.html#rules-for-parsing-non-negative-integers
+// https://html.spec.whatwg.org/C/#rules-for-parsing-non-negative-integers
 bool ParseHTMLNonNegativeInteger(const String& input, unsigned& value) {
   return ParseHTMLNonNegativeIntegerInternal(input, value) ==
          WTF::NumberParsingResult::kSuccess;
@@ -301,7 +301,7 @@ static Vector<double> ParseHTMLListOfFloatingPointNumbersInternal(
   return numbers;
 }
 
-// https://html.spec.whatwg.org/multipage/infrastructure.html#rules-for-parsing-a-list-of-floating-point-numbers
+// https://html.spec.whatwg.org/C/#rules-for-parsing-a-list-of-floating-point-numbers
 Vector<double> ParseHTMLListOfFloatingPointNumbers(const String& input) {
   unsigned length = input.length();
   if (!length || input.Is8Bit())
@@ -314,7 +314,7 @@ Vector<double> ParseHTMLListOfFloatingPointNumbers(const String& input) {
 static const char kCharsetString[] = "charset";
 static const size_t kCharsetLength = sizeof("charset") - 1;
 
-// https://html.spec.whatwg.org/multipage/infrastructure.html#extracting-character-encodings-from-meta-elements
+// https://html.spec.whatwg.org/C/#extracting-character-encodings-from-meta-elements
 String ExtractCharset(const String& value) {
   wtf_size_t pos = 0;
   unsigned length = value.length();
diff --git a/third_party/blink/renderer/core/html/parser/html_parser_idioms.h b/third_party/blink/renderer/core/html/parser/html_parser_idioms.h
index 1048d1572e0d23..58ff21f7d19258 100644
--- a/third_party/blink/renderer/core/html/parser/html_parser_idioms.h
+++ b/third_party/blink/renderer/core/html/parser/html_parser_idioms.h
@@ -63,14 +63,14 @@ CORE_EXPORT bool ParseHTMLInteger(const String&, int&);
 // http://www.whatwg.org/specs/web-apps/current-work/#rules-for-parsing-non-negative-integers
 CORE_EXPORT bool ParseHTMLNonNegativeInteger(const String&, unsigned&);
 
-// https://html.spec.whatwg.org/multipage/common-dom-interfaces.html#clamped-to-the-range
+// https://html.spec.whatwg.org/C/#clamped-to-the-range
 // without default value processing.
 bool ParseHTMLClampedNonNegativeInteger(const String&,
                                         unsigned min,
                                         unsigned max,
                                         unsigned&);
 
-// https://html.spec.whatwg.org/multipage/infrastructure.html#rules-for-parsing-a-list-of-floating-point-numbers
+// https://html.spec.whatwg.org/C/#rules-for-parsing-a-list-of-floating-point-numbers
 CORE_EXPORT Vector<double> ParseHTMLListOfFloatingPointNumbers(const String&);
 
 typedef Vector<std::pair<String, String>> HTMLAttributeList;
diff --git a/third_party/blink/renderer/core/html/parser/html_srcset_parser.cc b/third_party/blink/renderer/core/html/parser/html_srcset_parser.cc
index c9ece16511611d..637d43e8cbea21 100644
--- a/third_party/blink/renderer/core/html/parser/html_srcset_parser.cc
+++ b/third_party/blink/renderer/core/html/parser/html_srcset_parser.cc
@@ -71,7 +71,7 @@ struct DescriptorToken {
   int ToInt(const CharType* attribute, bool& is_valid) {
     unsigned position = 0;
     // Make sure the integer is a valid non-negative integer
-    // https://html.spec.whatwg.org/multipage/infrastructure.html#valid-non-negative-integer
+    // https://html.spec.whatwg.org/C/#valid-non-negative-integer
     unsigned length_excluding_descriptor = length - 1;
     while (position < length_excluding_descriptor) {
       if (!IsASCIIDigit(*(attribute + start + position))) {
@@ -87,7 +87,7 @@ struct DescriptorToken {
   template <typename CharType>
   float ToFloat(const CharType* attribute, bool& is_valid) {
     // Make sure the is a valid floating point number
-    // https://html.spec.whatwg.org/multipage/infrastructure.html#valid-floating-point-number
+    // https://html.spec.whatwg.org/C/#valid-floating-point-number
     unsigned length_excluding_descriptor = length - 1;
     if (length_excluding_descriptor > 0 && *(attribute + start) == '+') {
       is_valid = false;
diff --git a/third_party/blink/renderer/core/html/parser/html_tree_builder.cc b/third_party/blink/renderer/core/html/parser/html_tree_builder.cc
index 2938897d04ca7d..79a0fdae19c694 100644
--- a/third_party/blink/renderer/core/html/parser/html_tree_builder.cc
+++ b/third_party/blink/renderer/core/html/parser/html_tree_builder.cc
@@ -459,7 +459,7 @@ static void MapLoweredLocalNameToName(PrefixedNameToQualifiedNameMap* map,
 }
 
 // "Any other start tag" bullet in
-// https://html.spec.whatwg.org/multipage/parsing.html#parsing-main-inforeign
+// https://html.spec.whatwg.org/C/#parsing-main-inforeign
 static void AdjustSVGTagNameCase(AtomicHTMLToken* token) {
   static PrefixedNameToQualifiedNameMap* case_map = nullptr;
   if (!case_map) {
@@ -490,12 +490,12 @@ static void AdjustAttributes(AtomicHTMLToken* token) {
   }
 }
 
-// https://html.spec.whatwg.org/multipage/parsing.html#adjust-svg-attributes
+// https://html.spec.whatwg.org/C/#adjust-svg-attributes
 static void AdjustSVGAttributes(AtomicHTMLToken* token) {
   AdjustAttributes<svg_names::GetAttrs, svg_names::kAttrsCount>(token);
 }
 
-// https://html.spec.whatwg.org/multipage/parsing.html#adjust-mathml-attributes
+// https://html.spec.whatwg.org/C/#adjust-mathml-attributes
 static void AdjustMathMLAttributes(AtomicHTMLToken* token) {
   AdjustAttributes<mathml_names::GetAttrs, mathml_names::kAttrsCount>(token);
 }
diff --git a/third_party/blink/renderer/core/html/parser/html_tree_builder_simulator.cc b/third_party/blink/renderer/core/html/parser/html_tree_builder_simulator.cc
index 24ff8c3ae9c75a..73e44eb7386670 100644
--- a/third_party/blink/renderer/core/html/parser/html_tree_builder_simulator.cc
+++ b/third_party/blink/renderer/core/html/parser/html_tree_builder_simulator.cc
@@ -252,7 +252,7 @@ HTMLTreeBuilderSimulator::SimulatedToken HTMLTreeBuilderSimulator::Simulate(
   return simulated_token;
 }
 
-// https://html.spec.whatwg.org/multipage/parsing.html#html-integration-point
+// https://html.spec.whatwg.org/C/#html-integration-point
 bool HTMLTreeBuilderSimulator::IsHTMLIntegrationPointForStartTag(
     const CompactHTMLToken& token) const {
   DCHECK(token.GetType() == HTMLToken::kStartTag) << token.GetType();
@@ -278,7 +278,7 @@ bool HTMLTreeBuilderSimulator::IsHTMLIntegrationPointForStartTag(
   return false;
 }
 
-// https://html.spec.whatwg.org/multipage/parsing.html#html-integration-point
+// https://html.spec.whatwg.org/C/#html-integration-point
 bool HTMLTreeBuilderSimulator::IsHTMLIntegrationPointForEndTag(
     const CompactHTMLToken& token) const {
   if (token.GetType() != HTMLToken::kEndTag)
diff --git a/third_party/blink/renderer/core/html/rel_list.cc b/third_party/blink/renderer/core/html/rel_list.cc
index f279eefdb83d62..254b3ef24d741a 100644
--- a/third_party/blink/renderer/core/html/rel_list.cc
+++ b/third_party/blink/renderer/core/html/rel_list.cc
@@ -40,7 +40,7 @@ static HashSet<AtomicString>& SupportedTokensAnchorAndArea() {
 
 bool RelList::ValidateTokenValue(const AtomicString& token_value,
                                  ExceptionState&) const {
-  //  https://html.spec.whatwg.org/multipage/links.html#linkTypes
+  //  https://html.spec.whatwg.org/C/#linkTypes
   if (GetElement().HasTagName(html_names::kLinkTag)) {
     if (SupportedTokensLink().Contains(token_value) ||
         token_value == "modulepreload") {
diff --git a/third_party/blink/renderer/core/html/table_constants.h b/third_party/blink/renderer/core/html/table_constants.h
index cbb7fb2842c3ae..9cb86a0aeff8d1 100644
--- a/third_party/blink/renderer/core/html/table_constants.h
+++ b/third_party/blink/renderer/core/html/table_constants.h
@@ -7,14 +7,14 @@
 
 namespace blink {
 
-// https://html.spec.whatwg.org/multipage/tables.html#dom-colgroup-span
-// https://html.spec.whatwg.org/multipage/tables.html#dom-col-span
-// https://html.spec.whatwg.org/multipage/tables.html#dom-tdth-colspan
+// https://html.spec.whatwg.org/C/#dom-colgroup-span
+// https://html.spec.whatwg.org/C/#dom-col-span
+// https://html.spec.whatwg.org/C/#dom-tdth-colspan
 constexpr unsigned kDefaultColSpan = 1u;
 constexpr unsigned kMinColSpan = 1u;
 constexpr unsigned kMaxColSpan = 1000u;
 
-// https://html.spec.whatwg.org/multipage/tables.html#dom-tdth-rowspan
+// https://html.spec.whatwg.org/C/#dom-tdth-rowspan
 constexpr unsigned kDefaultRowSpan = 1u;
 constexpr unsigned kMaxRowSpan = 65534u;
 constexpr unsigned kMinRowSpan = 0;
diff --git a/third_party/blink/renderer/core/html/track/automatic_track_selection.cc b/third_party/blink/renderer/core/html/track/automatic_track_selection.cc
index a52ac2003a20f3..792173ddea8e84 100644
--- a/third_party/blink/renderer/core/html/track/automatic_track_selection.cc
+++ b/third_party/blink/renderer/core/html/track/automatic_track_selection.cc
@@ -141,7 +141,7 @@ void AutomaticTrackSelection::EnableDefaultMetadataTextTracks(
     const TrackGroup& group) {
   DCHECK(group.tracks.size());
 
-  // https://html.spec.whatwg.org/multipage/embedded-content.html#honor-user-preferences-for-automatic-text-track-selection
+  // https://html.spec.whatwg.org/C/#honor-user-preferences-for-automatic-text-track-selection
 
   // 4. If there are any text tracks in the media element's list of text
   // tracks whose text track kind is metadata that correspond to track
diff --git a/third_party/blink/renderer/core/html/track/text_track.cc b/third_party/blink/renderer/core/html/track/text_track.cc
index 7a05be9cb9cab2..6bc0fe0a9e6f8f 100644
--- a/third_party/blink/renderer/core/html/track/text_track.cc
+++ b/third_party/blink/renderer/core/html/track/text_track.cc
@@ -217,7 +217,7 @@ void TextTrack::addCue(TextTrackCue* cue) {
   if (std::isnan(cue->startTime()) || std::isnan(cue->endTime()))
     return;
 
-  // https://html.spec.whatwg.org/multipage/embedded-content.html#dom-texttrack-addcue
+  // https://html.spec.whatwg.org/C/#dom-texttrack-addcue
 
   // The addCue(cue) method of TextTrack objects, when invoked, must run the
   // following steps:
@@ -242,7 +242,7 @@ void TextTrack::addCue(TextTrackCue* cue) {
 void TextTrack::removeCue(TextTrackCue* cue, ExceptionState& exception_state) {
   DCHECK(cue);
 
-  // https://html.spec.whatwg.org/multipage/embedded-content.html#dom-texttrack-removecue
+  // https://html.spec.whatwg.org/C/#dom-texttrack-removecue
 
   // The removeCue(cue) method of TextTrack objects, when invoked, must run the
   // following steps:
diff --git a/third_party/blink/renderer/core/html/track/track_event.idl b/third_party/blink/renderer/core/html/track/track_event.idl
index ac013fb58be391..4bf135ebc9da47 100644
--- a/third_party/blink/renderer/core/html/track/track_event.idl
+++ b/third_party/blink/renderer/core/html/track/track_event.idl
@@ -23,7 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/embedded-content.html#the-trackevent-interface
+// https://html.spec.whatwg.org/C/#the-trackevent-interface
 
 [
     Constructor(DOMString type, optional TrackEventInit eventInitDict)
diff --git a/third_party/blink/renderer/core/html/track/track_event_init.idl b/third_party/blink/renderer/core/html/track/track_event_init.idl
index f37955afca6995..bb0611ae8907de 100644
--- a/third_party/blink/renderer/core/html/track/track_event_init.idl
+++ b/third_party/blink/renderer/core/html/track/track_event_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/embedded-content.html#the-trackevent-interface
+// https://html.spec.whatwg.org/C/#the-trackevent-interface
 
 dictionary TrackEventInit : EventInit {
     (VideoTrack or AudioTrack or TextTrack)? track;
diff --git a/third_party/blink/renderer/core/imagebitmap/image_bitmap.idl b/third_party/blink/renderer/core/imagebitmap/image_bitmap.idl
index c27b0b3b999a9e..706633c4674f58 100644
--- a/third_party/blink/renderer/core/imagebitmap/image_bitmap.idl
+++ b/third_party/blink/renderer/core/imagebitmap/image_bitmap.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/imagebitmap-and-animations.html#images-2
+// https://html.spec.whatwg.org/C/#images-2
 
 [
     Exposed=(Window,Worker),
diff --git a/third_party/blink/renderer/core/input/mouse_event_manager.cc b/third_party/blink/renderer/core/input/mouse_event_manager.cc
index e1ca5a0b62ee7c..756593f516a348 100644
--- a/third_party/blink/renderer/core/input/mouse_event_manager.cc
+++ b/third_party/blink/renderer/core/input/mouse_event_manager.cc
@@ -1036,7 +1036,7 @@ WebInputEventResult MouseEventManager::DispatchDragEvent(
     return WebInputEventResult::kNotHandled;
 
   // We should be setting relatedTarget correctly following the spec:
-  // https://html.spec.whatwg.org/multipage/interaction.html#dragevent
+  // https://html.spec.whatwg.org/C/#dragevent
   // At the same time this should prevent exposing a node from another document.
   if (related_target &&
       related_target->GetDocument() != drag_target->GetDocument())
diff --git a/third_party/blink/renderer/core/input/touch.idl b/third_party/blink/renderer/core/input/touch.idl
index af13543f0f85bc..223edc2c1d323e 100644
--- a/third_party/blink/renderer/core/input/touch.idl
+++ b/third_party/blink/renderer/core/input/touch.idl
@@ -44,6 +44,6 @@
     readonly attribute float force;
 
     // Canvas Hit Regions
-    // https://html.spec.whatwg.org/multipage/scripting.html#Touch-partial
+    // https://html.spec.whatwg.org/C/#Touch-partial
     [RuntimeEnabled=CanvasHitRegion] readonly attribute DOMString? region;
 };
diff --git a/third_party/blink/renderer/core/layout/layout_table.h b/third_party/blink/renderer/core/layout/layout_table.h
index 92feaf2f39c595..f8b75d15beb45c 100644
--- a/third_party/blink/renderer/core/layout/layout_table.h
+++ b/third_party/blink/renderer/core/layout/layout_table.h
@@ -57,7 +57,7 @@ enum TableHeightChangingValue { kTableHeightNotChanging, kTableHeightChanging };
 // - zero or more LayoutTableCaption
 // - zero or more LayoutTableSection
 // This is aligned with what HTML5 expects:
-// https://html.spec.whatwg.org/multipage/tables.html#the-table-element
+// https://html.spec.whatwg.org/C/#the-table-element
 // with one difference: we allow more than one caption as we follow what
 // CSS expects (https://bugs.webkit.org/show_bug.cgi?id=69773).
 // Those expectations are enforced by LayoutTable::addChild, that wraps unknown
diff --git a/third_party/blink/renderer/core/layout/ng/layout_ng_fieldset.cc b/third_party/blink/renderer/core/layout/ng/layout_ng_fieldset.cc
index eca59a4842cfab..78e976c0a08fcc 100644
--- a/third_party/blink/renderer/core/layout/ng/layout_ng_fieldset.cc
+++ b/third_party/blink/renderer/core/layout/ng/layout_ng_fieldset.cc
@@ -54,7 +54,7 @@ void LayoutNGFieldset::AddChild(LayoutObject* new_child,
     new_style->SetJustifyContent(StyleRef().JustifyContent());
 
     // TODO(mstensho): Inherit all properties listed here:
-    // https://html.spec.whatwg.org/multipage/rendering.html#the-fieldset-and-legend-elements
+    // https://html.spec.whatwg.org/C/#the-fieldset-and-legend-elements
 
     fieldset_content = LayoutBlock::CreateAnonymousWithParentAndDisplay(
         this, new_style->Display());
diff --git a/third_party/blink/renderer/core/layout/ng/ng_absolute_utils.cc b/third_party/blink/renderer/core/layout/ng/ng_absolute_utils.cc
index 19255eff95a372..57fe1f2cfded23 100644
--- a/third_party/blink/renderer/core/layout/ng/ng_absolute_utils.cc
+++ b/third_party/blink/renderer/core/layout/ng/ng_absolute_utils.cc
@@ -498,7 +498,7 @@ base::Optional<LayoutUnit> ComputeAbsoluteDialogYPosition(
 
   // This code implements <dialog> static position spec.
   // //
-  // https://html.spec.whatwg.org/multipage/interactive-elements.html#the-dialog-element
+  // https://html.spec.whatwg.org/C/#the-dialog-element
   HTMLDialogElement* dialog_node = ToHTMLDialogElement(dialog.GetNode());
   if (dialog_node->GetCenteringMode() == HTMLDialogElement::kNotCentered)
     return base::nullopt;
diff --git a/third_party/blink/renderer/core/layout/ng/ng_block_layout_algorithm.cc b/third_party/blink/renderer/core/layout/ng/ng_block_layout_algorithm.cc
index 018d7c57cf31f8..ab4f5eef36671f 100644
--- a/third_party/blink/renderer/core/layout/ng/ng_block_layout_algorithm.cc
+++ b/third_party/blink/renderer/core/layout/ng/ng_block_layout_algorithm.cc
@@ -574,7 +574,7 @@ scoped_refptr<NGLayoutResult> NGBlockLayoutAlgorithm::Layout() {
     // perform this calculation differently, e.g. by just ignoring the
     // *last* quirky margin.
     // TODO: revisit previous implementation to avoid changing behavior and
-    // https://html.spec.whatwg.org/multipage/rendering.html#margin-collapsing-quirks
+    // https://html.spec.whatwg.org/C/#margin-collapsing-quirks
     LayoutUnit margin_strut_sum = node_.IsQuirkyContainer()
                                       ? end_margin_strut.QuirkyContainerSum()
                                       : end_margin_strut.Sum();
diff --git a/third_party/blink/renderer/core/loader/image_loader.cc b/third_party/blink/renderer/core/loader/image_loader.cc
index 3a4d17887e83a7..8f64b828014dbc 100644
--- a/third_party/blink/renderer/core/loader/image_loader.cc
+++ b/third_party/blink/renderer/core/loader/image_loader.cc
@@ -832,7 +832,7 @@ void ImageLoader::ImageNotifyFinished(ImageResourceContent* resource) {
 
     // The error event should not fire if the image data update is a result of
     // environment change.
-    // https://html.spec.whatwg.org/multipage/embedded-content.html#the-img-element:the-img-element-55
+    // https://html.spec.whatwg.org/C/#the-img-element:the-img-element-55
     if (!suppress_error_events_)
       DispatchErrorEvent();
     return;
diff --git a/third_party/blink/renderer/core/loader/modulescript/module_script_loader.cc b/third_party/blink/renderer/core/loader/modulescript/module_script_loader.cc
index 66cc33955b36d4..bd5a923dca0489 100644
--- a/third_party/blink/renderer/core/loader/modulescript/module_script_loader.cc
+++ b/third_party/blink/renderer/core/loader/modulescript/module_script_loader.cc
@@ -93,7 +93,7 @@ void ModuleScriptLoader::Fetch(
                         level, custom_fetch_type);
 }
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-single-module-script
+// https://html.spec.whatwg.org/C/#fetch-a-single-module-script
 void ModuleScriptLoader::FetchInternal(
     const ModuleScriptFetchRequest& module_request,
     ResourceFetcher* fetch_client_settings_object_fetcher,
@@ -128,7 +128,7 @@ void ModuleScriptLoader::FetchInternal(
   // Step 6. "Set up the module script request given request and options."
   // [spec text]
   // [SMSR]
-  // https://html.spec.whatwg.org/multipage/webappapis.html#set-up-the-module-script-request
+  // https://html.spec.whatwg.org/C/#set-up-the-module-script-request
 
   // [SMSR] "... its parser metadata to options's parser metadata, ..."
   // [spec text]
@@ -195,7 +195,7 @@ void ModuleScriptLoader::FetchInternal(
   // -> set by ResourceFetcher
 
   // Note: The fetch request's "origin" isn't specified in
-  // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-single-module-script
+  // https://html.spec.whatwg.org/C/#fetch-a-single-module-script
   // Thus, the "origin" is "client" per
   // https://fetch.spec.whatwg.org/#concept-request-origin
 
diff --git a/third_party/blink/renderer/core/loader/modulescript/module_tree_linker.cc b/third_party/blink/renderer/core/loader/modulescript/module_tree_linker.cc
index 4a164a336d32df..3c93ce6d95d046 100644
--- a/third_party/blink/renderer/core/loader/modulescript/module_tree_linker.cc
+++ b/third_party/blink/renderer/core/loader/modulescript/module_tree_linker.cc
@@ -150,7 +150,7 @@ void ModuleTreeLinker::AdvanceState(State new_state) {
   }
 }
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-script-tree
+// https://html.spec.whatwg.org/C/#fetch-a-module-script-tree
 void ModuleTreeLinker::FetchRoot(const KURL& original_url,
                                  const ScriptFetchOptions& options) {
 #if DCHECK_IS_ON()
@@ -255,7 +255,7 @@ void ModuleTreeLinker::NotifyModuleLoadFinished(ModuleScript* module_script) {
 
   if (state_ == State::kFetchingSelf) {
     // Corresponds to top-level calls to
-    // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-the-descendants-of-and-instantiate-a-module-script
+    // https://html.spec.whatwg.org/C/#fetch-the-descendants-of-and-instantiate-a-module-script
     // i.e. [IMSGF] with the top-level module fetch flag set (external), or
     // Step 22 of "prepare a script" (inline).
     // |module_script| is the top-level module, and will be instantiated
@@ -365,7 +365,7 @@ void ModuleTreeLinker::FetchDescendants(ModuleScript* module_script) {
 
   // [FD] Step 6. Let options be the descendant script fetch options for module
   // script's fetch options.
-  // https://html.spec.whatwg.org/multipage/webappapis.html#descendant-script-fetch-options
+  // https://html.spec.whatwg.org/C/#descendant-script-fetch-options
   // the descendant script fetch options are a new script fetch options whose
   // items all have the same values, except for the integrity metadata, which is
   // instead the empty string.
diff --git a/third_party/blink/renderer/core/loader/modulescript/module_tree_linker.h b/third_party/blink/renderer/core/loader/modulescript/module_tree_linker.h
index c739ec7f51bb6e..c1cc15b2cc6028 100644
--- a/third_party/blink/renderer/core/loader/modulescript/module_tree_linker.h
+++ b/third_party/blink/renderer/core/loader/modulescript/module_tree_linker.h
@@ -124,7 +124,7 @@ class CORE_EXPORT ModuleTreeLinker final : public SingleModuleClient {
   State state_ = State::kInitial;
 
   // Correspond to _result_ in
-  // https://html.spec.whatwg.org/multipage/webappapis.html#internal-module-script-graph-fetching-procedure
+  // https://html.spec.whatwg.org/C/#internal-module-script-graph-fetching-procedure
   TraceWrapperMember<ModuleScript> result_;
 
   bool found_parse_error_ = false;
diff --git a/third_party/blink/renderer/core/loader/modulescript/worker_module_script_fetcher.cc b/third_party/blink/renderer/core/loader/modulescript/worker_module_script_fetcher.cc
index c0596eaea998f7..4ed3653d05f79d 100644
--- a/third_party/blink/renderer/core/loader/modulescript/worker_module_script_fetcher.cc
+++ b/third_party/blink/renderer/core/loader/modulescript/worker_module_script_fetcher.cc
@@ -17,7 +17,7 @@ WorkerModuleScriptFetcher::WorkerModuleScriptFetcher(
     WorkerGlobalScope* global_scope)
     : global_scope_(global_scope) {}
 
-// https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+// https://html.spec.whatwg.org/C/#worker-processing-model
 void WorkerModuleScriptFetcher::Fetch(
     FetchParameters& fetch_params,
     ResourceFetcher* fetch_client_settings_object_fetcher,
@@ -45,7 +45,7 @@ void WorkerModuleScriptFetcher::Trace(blink::Visitor* visitor) {
   visitor->Trace(global_scope_);
 }
 
-// https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+// https://html.spec.whatwg.org/C/#worker-processing-model
 void WorkerModuleScriptFetcher::NotifyFinished(Resource* resource) {
   DCHECK(global_scope_->IsContextThread());
   ClearResource();
diff --git a/third_party/blink/renderer/core/loader/modulescript/worker_module_script_fetcher.h b/third_party/blink/renderer/core/loader/modulescript/worker_module_script_fetcher.h
index 7819106617ba56..b0097ba9452b1f 100644
--- a/third_party/blink/renderer/core/loader/modulescript/worker_module_script_fetcher.h
+++ b/third_party/blink/renderer/core/loader/modulescript/worker_module_script_fetcher.h
@@ -14,8 +14,8 @@ class WorkerGlobalScope;
 // WorkerModuleScriptFetcher is an implementation of ModuleScriptFetcher
 // interface for WebWorkers. This implements the custom "perform the fetch" hook
 // defined in the HTML spec:
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetching-scripts-perform-fetch
-// https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+// https://html.spec.whatwg.org/C/#fetching-scripts-perform-fetch
+// https://html.spec.whatwg.org/C/#worker-processing-model
 class CORE_EXPORT WorkerModuleScriptFetcher final
     : public GarbageCollectedFinalized<WorkerModuleScriptFetcher>,
       public ModuleScriptFetcher {
diff --git a/third_party/blink/renderer/core/loader/modulescript/worklet_module_script_fetcher.h b/third_party/blink/renderer/core/loader/modulescript/worklet_module_script_fetcher.h
index 44c080ad0aff55..d82cd4e9c5b81d 100644
--- a/third_party/blink/renderer/core/loader/modulescript/worklet_module_script_fetcher.h
+++ b/third_party/blink/renderer/core/loader/modulescript/worklet_module_script_fetcher.h
@@ -16,7 +16,7 @@ class ResourceFetcher;
 // WorkletModuleScriptFetcher is an implementation of ModuleScriptFetcher
 // interface for Worklets. This implements the custom "perform the fetch" hook
 // defined in the Worklets spec:
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetching-scripts-perform-fetch
+// https://html.spec.whatwg.org/C/#fetching-scripts-perform-fetch
 // https://drafts.css-houdini.org/worklets/#fetch-a-worklet-script
 //
 // WorkletModuleScriptFetcher either fetchs a cached result from
diff --git a/third_party/blink/renderer/core/loader/preload_helper.cc b/third_party/blink/renderer/core/loader/preload_helper.cc
index 3514b1200cdaf5..59f14e0248b6be 100644
--- a/third_party/blink/renderer/core/loader/preload_helper.cc
+++ b/third_party/blink/renderer/core/loader/preload_helper.cc
@@ -284,7 +284,7 @@ Resource* PreloadHelper::PreloadIfNeeded(
                                      document.Fetcher());
 }
 
-// https://html.spec.whatwg.org/multipage/links.html#link-type-modulepreload
+// https://html.spec.whatwg.org/C/#link-type-modulepreload
 void PreloadHelper::ModulePreloadIfNeeded(
     const LinkLoadParameters& params,
     Document& document,
diff --git a/third_party/blink/renderer/core/messaging/README.md b/third_party/blink/renderer/core/messaging/README.md
index 2de9f394de1c47..3efb3d67cdd009 100644
--- a/third_party/blink/renderer/core/messaging/README.md
+++ b/third_party/blink/renderer/core/messaging/README.md
@@ -4,4 +4,4 @@ This directory contains:
 - The [Web Messaging API][1] implementation.
 - Structs and typemaps to efficiently pass SerializedScriptValue over mojo interfaces.
 
-[1]: https://html.spec.whatwg.org/multipage/web-messaging.html#channel-messaging
+[1]: https://html.spec.whatwg.org/C/#channel-messaging
diff --git a/third_party/blink/renderer/core/messaging/message_port.cc b/third_party/blink/renderer/core/messaging/message_port.cc
index a296a04f7a3380..be039ac265eb7c 100644
--- a/third_party/blink/renderer/core/messaging/message_port.cc
+++ b/third_party/blink/renderer/core/messaging/message_port.cc
@@ -243,7 +243,7 @@ MessagePortArray* MessagePort::EntanglePorts(
 MessagePortArray* MessagePort::EntanglePorts(
     ExecutionContext& context,
     WebVector<MessagePortChannel> channels) {
-  // https://html.spec.whatwg.org/multipage/comms.html#message-ports
+  // https://html.spec.whatwg.org/C/#message-ports
   // |ports| should be an empty array, not null even when there is no ports.
   wtf_size_t count = SafeCast<wtf_size_t>(channels.size());
   MessagePortArray* port_array = MakeGarbageCollected<MessagePortArray>(count);
diff --git a/third_party/blink/renderer/core/messaging/message_port.idl b/third_party/blink/renderer/core/messaging/message_port.idl
index 01d03add77c617..554b822687efd9 100644
--- a/third_party/blink/renderer/core/messaging/message_port.idl
+++ b/third_party/blink/renderer/core/messaging/message_port.idl
@@ -25,7 +25,7 @@
  *
  */
 
-// https://html.spec.whatwg.org/multipage/web-messaging.html#message-ports
+// https://html.spec.whatwg.org/C/#message-ports
 
 [
     ActiveScriptWrappable,
diff --git a/third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.idl b/third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.idl
index 115e1a3e431cce..42ed441e540347 100644
--- a/third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.idl
+++ b/third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/scripting.html#the-offscreencanvas-interface
+// https://html.spec.whatwg.org/C/#the-offscreencanvas-interface
 
 [
     Constructor([EnforceRange] unsigned long width, [EnforceRange] unsigned long height),
diff --git a/third_party/blink/renderer/core/page/create_window.cc b/third_party/blink/renderer/core/page/create_window.cc
index 1765b6563d0dac..5c3d84c6d3bd81 100644
--- a/third_party/blink/renderer/core/page/create_window.cc
+++ b/third_party/blink/renderer/core/page/create_window.cc
@@ -254,7 +254,7 @@ static Frame* CreateNewWindow(LocalFrame& opener_frame,
 
   if (base::FeatureList::IsEnabled(features::kOnionSoupDOMStorage)) {
     // TODO(dmurph): Don't copy session storage when features.noopener is true:
-    // https://html.spec.whatwg.org/multipage/browsers.html#copy-session-storage
+    // https://html.spec.whatwg.org/C/#copy-session-storage
     // https://crbug.com/771959
     CoreInitializer::GetInstance().CloneSessionStorage(old_page,
                                                        new_namespace_id);
diff --git a/third_party/blink/renderer/core/page/focus_controller.cc b/third_party/blink/renderer/core/page/focus_controller.cc
index 476a2e7a31c04b..8ef3cd21434f06 100644
--- a/third_party/blink/renderer/core/page/focus_controller.cc
+++ b/third_party/blink/renderer/core/page/focus_controller.cc
@@ -173,7 +173,7 @@ class ScopedFocusNavigation {
   // @return The focus element that comes after/before start element.
   //
   // [1]
-  // https://html.spec.whatwg.org/multipage/interaction.html#sequential-focus-navigation
+  // https://html.spec.whatwg.org/C/#sequential-focus-navigation
   // [2] https://w3c.github.io/webcomponents/spec/shadow/#focus-navigation
   Element* FindFocusableElement(WebFocusType type) {
     return (type == kWebFocusTypeForward) ? NextFocusableElement()
diff --git a/third_party/blink/renderer/core/page/page.h b/third_party/blink/renderer/core/page/page.h
index 47bea74708a4d5..0592b34635185a 100644
--- a/third_party/blink/renderer/core/page/page.h
+++ b/third_party/blink/renderer/core/page/page.h
@@ -125,7 +125,7 @@ class CORE_EXPORT Page final : public GarbageCollectedFinalized<Page>,
 
   // Returns pages related to the current browsing context (excluding the
   // current page).  See also
-  // https://html.spec.whatwg.org/multipage/browsers.html#unit-of-related-browsing-contexts
+  // https://html.spec.whatwg.org/C/#unit-of-related-browsing-contexts
   HeapVector<Member<Page>> RelatedPages();
 
   static void PlatformColorsChanged();
@@ -224,9 +224,9 @@ class CORE_EXPORT Page final : public GarbageCollectedFinalized<Page>,
 
   // Pausing is used to implement the "Optionally, pause while waiting for
   // the user to acknowledge the message" step of simple dialog processing:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#simple-dialogs
+  // https://html.spec.whatwg.org/C/#simple-dialogs
   //
-  // Per https://html.spec.whatwg.org/multipage/webappapis.html#pause, no loads
+  // Per https://html.spec.whatwg.org/C/#pause, no loads
   // are allowed to start/continue in this state, and all background processing
   // is also paused.
   bool Paused() const { return paused_; }
diff --git a/third_party/blink/renderer/core/page/scrolling/fragment_anchor.cc b/third_party/blink/renderer/core/page/scrolling/fragment_anchor.cc
index 993d6fc537057b..434d88d5282bb0 100644
--- a/third_party/blink/renderer/core/page/scrolling/fragment_anchor.cc
+++ b/third_party/blink/renderer/core/page/scrolling/fragment_anchor.cc
@@ -81,7 +81,7 @@ FragmentAnchor* FragmentAnchor::TryCreate(const KURL& url,
   if (!doc.IsSVGDocument())
     anchor_node = FindAnchorFromFragment(fragment, doc);
 
-  // https://html.spec.whatwg.org/multipage/browsing-the-web.html#the-indicated-part-of-the-document
+  // https://html.spec.whatwg.org/C/#the-indicated-part-of-the-document
   // 5. Let decodedFragment be the result of running UTF-8 decode without BOM
   // on fragmentBytes.
   if (!anchor_node) {
diff --git a/third_party/blink/renderer/core/paint/README.md b/third_party/blink/renderer/core/paint/README.md
index dbf3dc08122459..f435fbf51add21 100644
--- a/third_party/blink/renderer/core/paint/README.md
+++ b/third_party/blink/renderer/core/paint/README.md
@@ -26,7 +26,7 @@ are treated in different ways during painting:
     *   Stacking contexts: elements with non-auto z-indices or other properties
         that affect stacking e.g. transform, opacity, blend-mode.
 
-    *   Replaced normal-flow stacking elements: [replaced elements](https://html.spec.whatwg.org/multipage/rendering.html#replaced-elements)
+    *   Replaced normal-flow stacking elements: [replaced elements](https://html.spec.whatwg.org/C/#replaced-elements)
         that do not have non-auto z-index but are stacking contexts for
         elements below them. Right now the only example is SVG <foreignObject>.
         The difference between these elements and regular stacking contexts is
diff --git a/third_party/blink/renderer/core/script/README.md b/third_party/blink/renderer/core/script/README.md
index a7a6fbeea191c4..5f2e65d92210c9 100644
--- a/third_party/blink/renderer/core/script/README.md
+++ b/third_party/blink/renderer/core/script/README.md
@@ -8,16 +8,16 @@ The interaction between `<script>` elements and these components is controlled b
 
 This directory implements the following scripting concepts in the HTML spec:
 
-*   [`<script>` elements](https://html.spec.whatwg.org/multipage/scripting.html#the-script-element)
+*   [`<script>` elements](https://html.spec.whatwg.org/C/#the-script-element)
 *   Interactions between scripts and HTML/XML documents/parsers
-*   A part of [Scripting](https://html.spec.whatwg.org/multipage/webappapis.html#scripting)
-    * [scripts](https://html.spec.whatwg.org/multipage/webappapis.html#definitions-2)
-        * [classic scripts](https://html.spec.whatwg.org/multipage/webappapis.html#classic-script)
-        * [module scripts](https://html.spec.whatwg.org/multipage/webappapis.html#module-script)
-    * [Fetching](https://html.spec.whatwg.org/multipage/webappapis.html#fetching-scripts) scripts
-    * [creating](https://html.spec.whatwg.org/multipage/webappapis.html#creating-scripts) scripts
-    * [calling](https://html.spec.whatwg.org/multipage/webappapis.html#calling-scripts) scripts
-    * [Integration with the JavaScript module system](https://html.spec.whatwg.org/multipage/webappapis.html#integration-with-the-javascript-module-system)
+*   A part of [Scripting](https://html.spec.whatwg.org/C/#scripting)
+    * [scripts](https://html.spec.whatwg.org/C/#definitions-2)
+        * [classic scripts](https://html.spec.whatwg.org/C/#classic-script)
+        * [module scripts](https://html.spec.whatwg.org/C/#module-script)
+    * [Fetching](https://html.spec.whatwg.org/C/#fetching-scripts) scripts
+    * [creating](https://html.spec.whatwg.org/C/#creating-scripts) scripts
+    * [calling](https://html.spec.whatwg.org/C/#calling-scripts) scripts
+    * [Integration with the JavaScript module system](https://html.spec.whatwg.org/C/#integration-with-the-javascript-module-system)
 
 ## See Also
 
diff --git a/third_party/blink/renderer/core/script/classic_pending_script.h b/third_party/blink/renderer/core/script/classic_pending_script.h
index 50fa64fe813709..c9e135de65901c 100644
--- a/third_party/blink/renderer/core/script/classic_pending_script.h
+++ b/third_party/blink/renderer/core/script/classic_pending_script.h
@@ -16,7 +16,7 @@
 namespace blink {
 
 // PendingScript for a classic script
-// https://html.spec.whatwg.org/multipage/webappapis.html#classic-script.
+// https://html.spec.whatwg.org/C/#classic-script.
 //
 // TODO(kochi): The comment below is from pre-oilpan age and may not be correct
 // now.
@@ -29,7 +29,7 @@ class CORE_EXPORT ClassicPendingScript final : public PendingScript,
   USING_GARBAGE_COLLECTED_MIXIN(ClassicPendingScript);
 
  public:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-classic-script
+  // https://html.spec.whatwg.org/C/#fetch-a-classic-script
   //
   // For a script from an external file, calls ScriptResource::Fetch() and
   // creates ClassicPendingScript. Returns nullptr if Fetch() returns nullptr.
@@ -111,9 +111,9 @@ class CORE_EXPORT ClassicPendingScript final : public PendingScript,
   const ScriptFetchOptions options_;
 
   // "base url" snapshot taken at #prepare-a-script timing.
-  // https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script
+  // https://html.spec.whatwg.org/C/#prepare-a-script
   // which will eventually be used as #concept-script-base-url.
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-base-url
+  // https://html.spec.whatwg.org/C/#concept-script-base-url
   const KURL base_url_for_inline_script_;
 
   // "element's child text content" snapshot taken at
diff --git a/third_party/blink/renderer/core/script/document_modulator_impl_test.cc b/third_party/blink/renderer/core/script/document_modulator_impl_test.cc
index 49d89066d21282..415a10b7f93543 100644
--- a/third_party/blink/renderer/core/script/document_modulator_impl_test.cc
+++ b/third_party/blink/renderer/core/script/document_modulator_impl_test.cc
@@ -31,7 +31,7 @@ void DocumentModulatorImplTest::SetUp() {
 
 TEST_F(DocumentModulatorImplTest, ResolveModuleSpecifier) {
   // Taken from examples listed in
-  // https://html.spec.whatwg.org/multipage/webappapis.html#resolve-a-module-specifier
+  // https://html.spec.whatwg.org/C/#resolve-a-module-specifier
 
   // "The following are valid module specifiers according to the above
   // algorithm:"
diff --git a/third_party/blink/renderer/core/script/html_parser_script_runner.cc b/third_party/blink/renderer/core/script/html_parser_script_runner.cc
index b95c3fb863e2d8..5d9c294defa962 100644
--- a/third_party/blink/renderer/core/script/html_parser_script_runner.cc
+++ b/third_party/blink/renderer/core/script/html_parser_script_runner.cc
@@ -92,10 +92,10 @@ void TraceParserBlockingScript(const PendingScript* pending_script,
   // cases:
   // * the script's execution is blocked on the completed load of the script
   //   resource
-  //   (https://html.spec.whatwg.org/multipage/scripting.html#pending-parsing-blocking-script)
+  //   (https://html.spec.whatwg.org/C/#pending-parsing-blocking-script)
   // * the script's execution is blocked on the load of a style sheet or other
   //   resources that are blocking scripts
-  //   (https://html.spec.whatwg.org/multipage/semantics.html#a-style-sheet-that-is-blocking-scripts)
+  //   (https://html.spec.whatwg.org/C/#a-style-sheet-that-is-blocking-scripts)
   //
   // Both of these cases can introduce significant latency when loading a
   // web page, especially for users on slow connections, since the HTML parser
@@ -237,7 +237,7 @@ void HTMLParserScriptRunner::
 // Should be correspond to
 //
 // <specdef
-// href="https://html.spec.whatwg.org/multipage/scripting.html#execute-the-script-block">
+// href="https://html.spec.whatwg.org/C/#execute-the-script-block">
 //
 // but currently does more than specced, because historically this and
 // ExecutePendingParserBlockingScriptAndDispatchEvent() was the same method.
@@ -506,7 +506,7 @@ void HTMLParserScriptRunner::RequestDeferredScript(
 // The initial steps for 'An end tag whose tag name is "script"'
 // <specdef href="https://html.spec.whatwg.org/C/#scriptEndTag">
 // <specdef label="prepare-a-script"
-// href="https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script">
+// href="https://html.spec.whatwg.org/C/#prepare-a-script">
 void HTMLParserScriptRunner::ProcessScriptElementInternal(
     Element* script,
     const TextPosition& script_start_position) {
diff --git a/third_party/blink/renderer/core/script/html_parser_script_runner.h b/third_party/blink/renderer/core/script/html_parser_script_runner.h
index 9f6a56745506a7..b698180ea8cbb6 100644
--- a/third_party/blink/renderer/core/script/html_parser_script_runner.h
+++ b/third_party/blink/renderer/core/script/html_parser_script_runner.h
@@ -47,7 +47,7 @@ class ScriptLoader;
 // HTMLParserScriptRunner is responsible for for arranging the execution of
 // script elements inserted by the parser, according to the rules for
 // 'An end tag whose tag name is "script"':
-// https://html.spec.whatwg.org/multipage/parsing.html#scriptEndTag
+// https://html.spec.whatwg.org/C/#scriptEndTag
 //
 // If a script blocks parsing, this class is responsible for holding it, and
 // executing it when required.
@@ -134,10 +134,10 @@ class HTMLParserScriptRunner final
   Member<Document> document_;
   Member<HTMLParserScriptRunnerHost> host_;
 
-  // https://html.spec.whatwg.org/multipage/scripting.html#pending-parsing-blocking-script
+  // https://html.spec.whatwg.org/C/#pending-parsing-blocking-script
   TraceWrapperMember<PendingScript> parser_blocking_script_;
 
-  // https://html.spec.whatwg.org/multipage/scripting.html#list-of-scripts-that-will-execute-when-the-document-has-finished-parsing
+  // https://html.spec.whatwg.org/C/#list-of-scripts-that-will-execute-when-the-document-has-finished-parsing
   HeapDeque<TraceWrapperMember<PendingScript>>
       scripts_to_execute_after_parsing_;
 
diff --git a/third_party/blink/renderer/core/script/modulator.h b/third_party/blink/renderer/core/script/modulator.h
index 591b778749677e..2926e97a82a311 100644
--- a/third_party/blink/renderer/core/script/modulator.h
+++ b/third_party/blink/renderer/core/script/modulator.h
@@ -63,18 +63,18 @@ class CORE_EXPORT ModuleTreeClient
 };
 
 // spec: "top-level module fetch flag"
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetching-scripts-is-top-level
+// https://html.spec.whatwg.org/C/#fetching-scripts-is-top-level
 enum class ModuleGraphLevel { kTopLevelModuleFetch, kDependentModuleFetch };
 
 // spec: "custom peform the fetch hook"
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetching-scripts-perform-fetch
+// https://html.spec.whatwg.org/C/#fetching-scripts-perform-fetch
 enum class ModuleScriptCustomFetchType {
   // Fetch module scripts without invoking custom fetch steps.
   kNone,
 
   // Perform custom fetch steps for worker's constructor defined in the HTML
   // spec:
-  // https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+  // https://html.spec.whatwg.org/C/#worker-processing-model
   kWorkerConstructor,
 
   // Perform custom fetch steps for Worklet's addModule() function defined in
@@ -89,7 +89,7 @@ enum class ModuleScriptCustomFetchType {
 
 // A Modulator is an interface for "environment settings object" concept for
 // module scripts.
-// https://html.spec.whatwg.org/multipage/webappapis.html#environment-settings-object
+// https://html.spec.whatwg.org/C/#environment-settings-object
 //
 // A Modulator also serves as an entry point for various module spec algorithms.
 class CORE_EXPORT Modulator : public GarbageCollectedFinalized<Modulator>,
@@ -112,12 +112,12 @@ class CORE_EXPORT Modulator : public GarbageCollectedFinalized<Modulator>,
 
   virtual ScriptState* GetScriptState() = 0;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-bc-noscript
+  // https://html.spec.whatwg.org/C/#concept-bc-noscript
   // "scripting is disabled for settings's responsible browsing context"
   virtual bool IsScriptingDisabled() const = 0;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-script-tree
-  // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-worker-script-tree
+  // https://html.spec.whatwg.org/C/#fetch-a-module-script-tree
+  // https://html.spec.whatwg.org/C/#fetch-a-module-worker-script-tree
   // Note that |this| is the "module map settings object" and
   // ResourceFetcher represents "fetch client settings object"
   // used in the "fetch a module worker script graph" algorithm.
@@ -130,7 +130,7 @@ class CORE_EXPORT Modulator : public GarbageCollectedFinalized<Modulator>,
 
   // Asynchronously retrieve a module script from the module map, or fetch it
   // and put it in the map if it's not there already.
-  // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-single-module-script
+  // https://html.spec.whatwg.org/C/#fetch-a-single-module-script
   // Note that |this| is the "module map settings object" and
   // |fetch_client_settings_object_fetcher| represents
   // "fetch client settings object", which can be different from the
@@ -154,7 +154,7 @@ class CORE_EXPORT Modulator : public GarbageCollectedFinalized<Modulator>,
   // is still "fetching".
   virtual ModuleScript* GetFetchedModuleScript(const KURL&) = 0;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#resolve-a-module-specifier
+  // https://html.spec.whatwg.org/C/#resolve-a-module-specifier
   virtual KURL ResolveModuleSpecifier(const String& module_request,
                                       const KURL& base_url,
                                       String* failure_reason = nullptr) = 0;
@@ -165,7 +165,7 @@ class CORE_EXPORT Modulator : public GarbageCollectedFinalized<Modulator>,
                                   const ReferrerScriptInfo&,
                                   ScriptPromiseResolver*) = 0;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#hostgetimportmetaproperties
+  // https://html.spec.whatwg.org/C/#hostgetimportmetaproperties
   virtual ModuleImportMeta HostGetImportMetaProperties(ScriptModule) const = 0;
 
   virtual bool HasValidContext() = 0;
@@ -184,7 +184,7 @@ class CORE_EXPORT Modulator : public GarbageCollectedFinalized<Modulator>,
   enum class CaptureEvalErrorFlag : bool { kReport, kCapture };
 
   // ExecuteModule implements #run-a-module-script HTML spec algorithm.
-  // https://html.spec.whatwg.org/multipage/webappapis.html#run-a-module-script
+  // https://html.spec.whatwg.org/C/#run-a-module-script
   // CaptureEvalErrorFlag is used to implement "rethrow errors" parameter in
   // run-a-module-script.
   // - When "rethrow errors" is to be set, use kCapture for EvaluateModule().
diff --git a/third_party/blink/renderer/core/script/modulator_impl_base.cc b/third_party/blink/renderer/core/script/modulator_impl_base.cc
index 3dc622587795e9..88e99f8021eb6f 100644
--- a/third_party/blink/renderer/core/script/modulator_impl_base.cc
+++ b/third_party/blink/renderer/core/script/modulator_impl_base.cc
@@ -45,9 +45,9 @@ bool ModulatorImplBase::IsScriptingDisabled() const {
 }
 
 // <specdef label="fetch-a-module-script-tree"
-// href="https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-script-tree">
+// href="https://html.spec.whatwg.org/C/#fetch-a-module-script-tree">
 // <specdef label="fetch-a-module-worker-script-tree"
-// href="https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-worker-script-tree">
+// href="https://html.spec.whatwg.org/C/#fetch-a-module-worker-script-tree">
 void ModulatorImplBase::FetchTree(
     const KURL& url,
     ResourceFetcher* fetch_client_settings_object_fetcher,
diff --git a/third_party/blink/renderer/core/script/module_import_meta.h b/third_party/blink/renderer/core/script/module_import_meta.h
index 3d7a7cdf0a98e8..d6af2ba44f3549 100644
--- a/third_party/blink/renderer/core/script/module_import_meta.h
+++ b/third_party/blink/renderer/core/script/module_import_meta.h
@@ -11,7 +11,7 @@
 namespace blink {
 
 // Represents import.meta data structure, which is the return value of
-// https://html.spec.whatwg.org/multipage/webappapis.html#hostgetimportmetaproperties
+// https://html.spec.whatwg.org/C/#hostgetimportmetaproperties
 class CORE_EXPORT ModuleImportMeta final {
  public:
   explicit ModuleImportMeta(const String& url) : url_(url) {}
diff --git a/third_party/blink/renderer/core/script/module_map.cc b/third_party/blink/renderer/core/script/module_map.cc
index a48f1f21db0a6d..7e0f3e53f64fb9 100644
--- a/third_party/blink/renderer/core/script/module_map.cc
+++ b/third_party/blink/renderer/core/script/module_map.cc
@@ -15,7 +15,7 @@
 namespace blink {
 
 // Entry struct represents a value in "module map" spec object.
-// https://html.spec.whatwg.org/multipage/webappapis.html#module-map
+// https://html.spec.whatwg.org/C/#module-map
 class ModuleMap::Entry final : public GarbageCollectedFinalized<Entry>,
                                public NameClient,
                                public ModuleScriptLoaderClient {
diff --git a/third_party/blink/renderer/core/script/module_map.h b/third_party/blink/renderer/core/script/module_map.h
index 3949ceba0320d1..52457cdf9c82f4 100644
--- a/third_party/blink/renderer/core/script/module_map.h
+++ b/third_party/blink/renderer/core/script/module_map.h
@@ -26,7 +26,7 @@ enum class ModuleGraphLevel;
 enum class ModuleScriptCustomFetchType;
 
 // A ModuleMap implements "module map" spec.
-// https://html.spec.whatwg.org/multipage/webappapis.html#module-map
+// https://html.spec.whatwg.org/C/#module-map
 class CORE_EXPORT ModuleMap final : public GarbageCollected<ModuleMap>,
                                     public NameClient {
   class Entry;
@@ -41,7 +41,7 @@ class CORE_EXPORT ModuleMap final : public GarbageCollected<ModuleMap>,
   void Trace(blink::Visitor*);
   const char* NameInHeapSnapshot() const override { return "ModuleMap"; }
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-single-module-script
+  // https://html.spec.whatwg.org/C/#fetch-a-single-module-script
   void FetchSingleModuleScript(
       const ModuleScriptFetchRequest&,
       ResourceFetcher* fetch_client_settings_object_fetcher,
diff --git a/third_party/blink/renderer/core/script/module_pending_script.h b/third_party/blink/renderer/core/script/module_pending_script.h
index d1c1576448c266..b75a48f17ece4b 100644
--- a/third_party/blink/renderer/core/script/module_pending_script.h
+++ b/third_party/blink/renderer/core/script/module_pending_script.h
@@ -46,7 +46,7 @@ class ModulePendingScriptTreeClient final : public ModuleTreeClient {
 };
 
 // PendingScript for a module script
-// https://html.spec.whatwg.org/multipage/webappapis.html#module-script.
+// https://html.spec.whatwg.org/C/#module-script.
 class CORE_EXPORT ModulePendingScript : public PendingScript {
  public:
   static ModulePendingScript* Create(ScriptElementBase* element,
diff --git a/third_party/blink/renderer/core/script/module_script.h b/third_party/blink/renderer/core/script/module_script.h
index 02c3e13682b763..305035fc1cc173 100644
--- a/third_party/blink/renderer/core/script/module_script.h
+++ b/third_party/blink/renderer/core/script/module_script.h
@@ -22,10 +22,10 @@
 namespace blink {
 
 // ModuleScript is a model object for the "module script" spec concept.
-// https://html.spec.whatwg.org/multipage/webappapis.html#module-script
+// https://html.spec.whatwg.org/C/#module-script
 class CORE_EXPORT ModuleScript final : public Script, public NameClient {
  public:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#creating-a-module-script
+  // https://html.spec.whatwg.org/C/#creating-a-module-script
   static ModuleScript* Create(
       const ParkableString& source_text,
       Modulator*,
@@ -95,16 +95,16 @@ class CORE_EXPORT ModuleScript final : public Script, public NameClient {
   friend class ModulatorImplBase;
   friend class ModuleTreeLinkerTestModulator;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#settings-object
+  // https://html.spec.whatwg.org/C/#settings-object
   Member<Modulator> settings_object_;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-record
+  // https://html.spec.whatwg.org/C/#concept-script-record
   // TODO(keishi): Visitor only defines a trace method for v8::Value so this
   // needs to be cast.
   GC_PLUGIN_IGNORE("757708")
   TraceWrapperV8Reference<v8::Module> record_;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-parse-error
+  // https://html.spec.whatwg.org/C/#concept-script-parse-error
   //
   // |record_|, |parse_error_| and |error_to_rethrow_| are wrapper traced and
   // kept alive via one or more of following reference graphs:
@@ -141,7 +141,7 @@ class CORE_EXPORT ModuleScript final : public Script, public NameClient {
   //   will require moderate code changes (e.g. to move compilation timing).
   TraceWrapperV8Reference<v8::Value> parse_error_;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-error-to-rethrow
+  // https://html.spec.whatwg.org/C/#concept-script-error-to-rethrow
   TraceWrapperV8Reference<v8::Value> error_to_rethrow_;
 
   // For CSP check.
diff --git a/third_party/blink/renderer/core/script/pending_script.h b/third_party/blink/renderer/core/script/pending_script.h
index 31663d11807071..f94549326811ae 100644
--- a/third_party/blink/renderer/core/script/pending_script.h
+++ b/third_party/blink/renderer/core/script/pending_script.h
@@ -60,7 +60,7 @@ class CORE_EXPORT PendingScriptClient : public GarbageCollectedMixin {
 // ScriptLoader creates a PendingScript in ScriptLoader::PrepareScript(), and
 // a Script is created via PendingScript::GetSource() when it becomes ready.
 // When "script is ready"
-// https://html.spec.whatwg.org/multipage/scripting.html#the-script-is-ready,
+// https://html.spec.whatwg.org/C/#the-script-is-ready,
 // PendingScriptClient is notified.
 class CORE_EXPORT PendingScript
     : public GarbageCollectedFinalized<PendingScript>,
@@ -91,7 +91,7 @@ class CORE_EXPORT PendingScript
   // Returns nullptr when "script's script is null", i.e. an error occurred.
   virtual Script* GetSource(const KURL& document_url) const = 0;
 
-  // https://html.spec.whatwg.org/multipage/scripting.html#the-script-is-ready
+  // https://html.spec.whatwg.org/C/#the-script-is-ready
   virtual bool IsReady() const = 0;
   virtual bool IsExternal() const = 0;
   virtual bool WasCanceled() const = 0;
@@ -101,7 +101,7 @@ class CORE_EXPORT PendingScript
 
   // Used only for tracing, and can return a null URL.
   // TODO(hiroshige): It's preferable to return the base URL consistently
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-base-url
+  // https://html.spec.whatwg.org/C/#concept-script-base-url
   // but it requires further refactoring.
   virtual KURL UrlForTracing() const = 0;
 
@@ -129,7 +129,7 @@ class CORE_EXPORT PendingScript
     return created_during_document_write_;
   }
 
-  // https://html.spec.whatwg.org/multipage/scripting.html#execute-the-script-block
+  // https://html.spec.whatwg.org/C/#execute-the-script-block
   // The single entry point of script execution.
   // PendingScript::Dispose() is called in ExecuteScriptBlock().
   //
diff --git a/third_party/blink/renderer/core/script/script.h b/third_party/blink/renderer/core/script/script.h
index 7ef296000572aa..70e4affcc3feac 100644
--- a/third_party/blink/renderer/core/script/script.h
+++ b/third_party/blink/renderer/core/script/script.h
@@ -17,7 +17,7 @@ namespace blink {
 class LocalFrame;
 class SecurityOrigin;
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#concept-script
+// https://html.spec.whatwg.org/C/#concept-script
 class CORE_EXPORT Script : public GarbageCollectedFinalized<Script> {
  public:
   virtual void Trace(blink::Visitor* visitor) {}
@@ -26,9 +26,9 @@ class CORE_EXPORT Script : public GarbageCollectedFinalized<Script> {
 
   virtual mojom::ScriptType GetScriptType() const = 0;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#run-a-classic-script
+  // https://html.spec.whatwg.org/C/#run-a-classic-script
   // or
-  // https://html.spec.whatwg.org/multipage/webappapis.html#run-a-module-script,
+  // https://html.spec.whatwg.org/C/#run-a-module-script,
   // depending on the script type.
   virtual void RunScript(LocalFrame*, const SecurityOrigin*) const = 0;
 
@@ -43,10 +43,10 @@ class CORE_EXPORT Script : public GarbageCollectedFinalized<Script> {
       : fetch_options_(fetch_options), base_url_(base_url) {}
 
  private:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-script-fetch-options
+  // https://html.spec.whatwg.org/C/#concept-script-script-fetch-options
   const ScriptFetchOptions fetch_options_;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-base-url
+  // https://html.spec.whatwg.org/C/#concept-script-base-url
   const KURL base_url_;
 };
 
diff --git a/third_party/blink/renderer/core/script/script_loader.cc b/third_party/blink/renderer/core/script/script_loader.cc
index 77c49c877a7028..2bd15a1b6e505d 100644
--- a/third_party/blink/renderer/core/script/script_loader.cc
+++ b/third_party/blink/renderer/core/script/script_loader.cc
@@ -201,13 +201,13 @@ bool ScriptLoader::BlockForNoModule(mojom::ScriptType script_type,
 }
 
 // Corresponds to
-// https://html.spec.whatwg.org/multipage/urls-and-fetching.html#module-script-credentials-mode
+// https://html.spec.whatwg.org/C/#module-script-credentials-mode
 // which is a translation of the CORS settings attribute in the context of
 // module scripts. This is used in:
 //   - Step 17 of
-//     https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script
+//     https://html.spec.whatwg.org/C/#prepare-a-script
 //   - Step 6 of obtaining a preloaded module script
-//     https://html.spec.whatwg.org/multipage/links.html#link-type-modulepreload.
+//     https://html.spec.whatwg.org/C/#link-type-modulepreload.
 network::mojom::FetchCredentialsMode ScriptLoader::ModuleScriptCredentialsMode(
     CrossOriginAttributeValue cross_origin) {
   switch (cross_origin) {
@@ -749,7 +749,7 @@ bool ScriptLoader::PrepareScript(const TextPosition& script_start_position,
   return true;
 }
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-classic-script
+// https://html.spec.whatwg.org/C/#fetch-a-classic-script
 void ScriptLoader::FetchClassicScript(const KURL& url,
                                       Document& element_document,
                                       const ScriptFetchOptions& options,
diff --git a/third_party/blink/renderer/core/script/script_loader.h b/third_party/blink/renderer/core/script/script_loader.h
index 689d62b12a0525..71607bbb87e2c4 100644
--- a/third_party/blink/renderer/core/script/script_loader.h
+++ b/third_party/blink/renderer/core/script/script_loader.h
@@ -82,7 +82,7 @@ class CORE_EXPORT ScriptLoader final
   static network::mojom::FetchCredentialsMode ModuleScriptCredentialsMode(
       CrossOriginAttributeValue);
 
-  // https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script
+  // https://html.spec.whatwg.org/C/#prepare-a-script
   bool PrepareScript(const TextPosition& script_start_position =
                          TextPosition::MinimumPosition(),
                      LegacyTypeSupport = kDisallowLegacyTypeInTypeAttribute);
@@ -120,16 +120,16 @@ class CORE_EXPORT ScriptLoader final
   bool IsScriptForEventSupported() const;
 
   // FetchClassicScript corresponds to Step 21.6 of
-  // https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script
+  // https://html.spec.whatwg.org/C/#prepare-a-script
   // and must NOT be called from outside of PendingScript().
   //
-  // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-classic-script
+  // https://html.spec.whatwg.org/C/#fetch-a-classic-script
   void FetchClassicScript(const KURL&,
                           Document&,
                           const ScriptFetchOptions&,
                           CrossOriginAttributeValue,
                           const WTF::TextEncoding&);
-  // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-script-tree
+  // https://html.spec.whatwg.org/C/#fetch-a-module-script-tree
   void FetchModuleScriptTree(const KURL&,
                              ResourceFetcher*,
                              Modulator*,
@@ -143,36 +143,36 @@ class CORE_EXPORT ScriptLoader final
 
   Member<ScriptElementBase> element_;
 
-  // https://html.spec.whatwg.org/multipage/scripting.html#script-processing-model
+  // https://html.spec.whatwg.org/C/#script-processing-model
   // "A script element has several associated pieces of state.":
 
   // <spec
-  // href="https://html.spec.whatwg.org/multipage/scripting.html#already-started">
+  // href="https://html.spec.whatwg.org/C/#already-started">
   // ... Initially, script elements must have this flag unset ...</spec>
   bool already_started_ = false;
 
   // <spec
-  // href="https://html.spec.whatwg.org/multipage/scripting.html#parser-inserted">
+  // href="https://html.spec.whatwg.org/C/#parser-inserted">
   // ... Initially, script elements must have this flag unset. ...</spec>
   bool parser_inserted_ = false;
 
   // <spec
-  // href="https://html.spec.whatwg.org/multipage/scripting.html#non-blocking">
+  // href="https://html.spec.whatwg.org/C/#non-blocking">
   // ... Initially, script elements must have this flag set. ...</spec>
   bool non_blocking_ = true;
 
   // <spec
-  // href="https://html.spec.whatwg.org/multipage/scripting.html#ready-to-be-parser-executed">
+  // href="https://html.spec.whatwg.org/C/#ready-to-be-parser-executed">
   // ... Initially, script elements must have this flag unset ...</spec>
   bool ready_to_be_parser_executed_ = false;
 
   // <spec
-  // href="https://html.spec.whatwg.org/multipage/scripting.html#concept-script-type">
+  // href="https://html.spec.whatwg.org/C/#concept-script-type">
   // ... It is determined when the script is prepared, ...</spec>
   mojom::ScriptType script_type_ = mojom::ScriptType::kClassic;
 
   // <spec
-  // href="https://html.spec.whatwg.org/multipage/scripting.html#concept-script-external">
+  // href="https://html.spec.whatwg.org/C/#concept-script-external">
   // ... It is determined when the script is prepared, ...</spec>
   bool is_external_script_ = false;
 
diff --git a/third_party/blink/renderer/core/script/script_module_resolver_impl.h b/third_party/blink/renderer/core/script/script_module_resolver_impl.h
index 6249cec0e50684..e4fa7357fd059b 100644
--- a/third_party/blink/renderer/core/script/script_module_resolver_impl.h
+++ b/third_party/blink/renderer/core/script/script_module_resolver_impl.h
@@ -47,7 +47,7 @@ class CORE_EXPORT ScriptModuleResolverImpl final
   ModuleScript* GetHostDefined(const ScriptModule&) const final;
 
   // Implements "Runtime Semantics: HostResolveImportedModule" per HTML spec.
-  // https://html.spec.whatwg.org/multipage/webappapis.html#hostresolveimportedmodule(referencingscriptormodule,-specifier))
+  // https://html.spec.whatwg.org/C/#hostresolveimportedmodule(referencingscriptormodule,-specifier))
   ScriptModule Resolve(const String& specifier,
                        const ScriptModule& referrer,
                        ExceptionState&) final;
diff --git a/third_party/blink/renderer/core/script/script_scheduling_type.h b/third_party/blink/renderer/core/script/script_scheduling_type.h
index 869e28575bcbac..928143ec8955e0 100644
--- a/third_party/blink/renderer/core/script/script_scheduling_type.h
+++ b/third_party/blink/renderer/core/script/script_scheduling_type.h
@@ -10,7 +10,7 @@ namespace blink {
 // Type of <script>'s scheduling.
 //
 // In the spec, this is determined which clause of Step 25 of
-// https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script
+// https://html.spec.whatwg.org/C/#prepare-a-script
 // is taken.
 //
 // The enum values are used in histograms and thus do not change existing
diff --git a/third_party/blink/renderer/core/script/xml_parser_script_runner.cc b/third_party/blink/renderer/core/script/xml_parser_script_runner.cc
index 4b13772c642af2..91340e9063c155 100644
--- a/third_party/blink/renderer/core/script/xml_parser_script_runner.cc
+++ b/third_party/blink/renderer/core/script/xml_parser_script_runner.cc
@@ -14,9 +14,9 @@ namespace blink {
 
 // Spec links:
 // <specdef label="Parsing"
-// href="https://html.spec.whatwg.org/multipage/xhtml.html#parsing-xhtml-documents">
+// href="https://html.spec.whatwg.org/C/#parsing-xhtml-documents">
 // <specdef label="Prepare"
-// href="https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script">
+// href="https://html.spec.whatwg.org/C/#prepare-a-script">
 
 XMLParserScriptRunner::XMLParserScriptRunner(XMLParserScriptRunnerHost* host)
     : host_(host) {}
diff --git a/third_party/blink/renderer/core/script/xml_parser_script_runner.h b/third_party/blink/renderer/core/script/xml_parser_script_runner.h
index 69db30b585bccb..d682bd52aad760 100644
--- a/third_party/blink/renderer/core/script/xml_parser_script_runner.h
+++ b/third_party/blink/renderer/core/script/xml_parser_script_runner.h
@@ -17,7 +17,7 @@ class XMLParserScriptRunnerHost;
 // XMLParserScriptRunner implements the interaction between an XML parser
 // (XMLDocumentParser) and <script> elements and their loading/execution.
 //
-// https://html.spec.whatwg.org/multipage/xhtml.html#parsing-xhtml-documents
+// https://html.spec.whatwg.org/C/#parsing-xhtml-documents
 class XMLParserScriptRunner final
     : public GarbageCollectedFinalized<XMLParserScriptRunner>,
       public PendingScriptClient {
@@ -42,7 +42,7 @@ class XMLParserScriptRunner final
   // from PendingScriptClient
   void PendingScriptFinished(PendingScript*) override;
 
-  // https://html.spec.whatwg.org/multipage/scripting.html#pending-parsing-blocking-script
+  // https://html.spec.whatwg.org/C/#pending-parsing-blocking-script
   // TODO(crbug/717643): Support module scripts, and turn this into
   // TraceWrapperMember<>.
   Member<PendingScript> parser_blocking_script_;
@@ -50,7 +50,7 @@ class XMLParserScriptRunner final
   Member<XMLParserScriptRunnerHost> host_;
 
   // TODO(crbug/717643): Implement
-  // https://html.spec.whatwg.org/multipage/scripting.html#list-of-scripts-that-will-execute-when-the-document-has-finished-parsing
+  // https://html.spec.whatwg.org/C/#list-of-scripts-that-will-execute-when-the-document-has-finished-parsing
   DISALLOW_COPY_AND_ASSIGN(XMLParserScriptRunner);
 };
 
diff --git a/third_party/blink/renderer/core/testing/internals.idl b/third_party/blink/renderer/core/testing/internals.idl
index c84d70c127fb46..764185c5270c31 100644
--- a/third_party/blink/renderer/core/testing/internals.idl
+++ b/third_party/blink/renderer/core/testing/internals.idl
@@ -416,7 +416,7 @@
     // element mechanism.
     [RaisesException] void addEmbedderCustomElementName(DOMString name);
 
-    // https://html.spec.whatwg.org/multipage/webappapis.html#resolve-a-module-specifier
+    // https://html.spec.whatwg.org/C/#resolve-a-module-specifier
     // Throws TypeError on error.
     // Used for testing Import Maps https://github.com/domenic/import-maps
     [RaisesException] DOMString resolveModuleSpecifier(DOMString specifier, DOMString base_url, Document document);
diff --git a/third_party/blink/renderer/core/url/README.md b/third_party/blink/renderer/core/url/README.md
index 440f7498dbaf15..4e5733af2df9a3 100644
--- a/third_party/blink/renderer/core/url/README.md
+++ b/third_party/blink/renderer/core/url/README.md
@@ -6,9 +6,9 @@ This directory contains:
 - the object URL methods for [Blob][5], [Media Source Extensions][6] and [Media Capture and Streams][7]
 
 [1]: https://url.spec.whatwg.org/
-[2]: https://html.spec.whatwg.org/multipage/history.html#the-location-interface
-[3]: https://html.spec.whatwg.org/multipage/workers.html#worker-locations
-[4]: https://html.spec.whatwg.org/multipage/links.html#api-for-a-and-area-elements
+[2]: https://html.spec.whatwg.org/C/#the-location-interface
+[3]: https://html.spec.whatwg.org/C/#worker-locations
+[4]: https://html.spec.whatwg.org/C/#api-for-a-and-area-elements
 [5]: https://w3c.github.io/FileAPI/#dfn-createObjectURL
 [6]: http://w3c.github.io/media-source/#dom-url-createobjecturl
 [7]: https://w3c.github.io/mediacapture-main/
diff --git a/third_party/blink/renderer/core/workers/README.md b/third_party/blink/renderer/core/workers/README.md
index 06797198929e8c..f17260abadf0c8 100644
--- a/third_party/blink/renderer/core/workers/README.md
+++ b/third_party/blink/renderer/core/workers/README.md
@@ -1,4 +1,4 @@
-This directory contains the base implementation of all worker and worklet types. Also, this contains the implementation of the [Web Workers API](https://html.spec.whatwg.org/multipage/workers.html#workers) (Dedicated Worker and Shared Worker) and [Worklets API](https://drafts.css-houdini.org/worklets/).
+This directory contains the base implementation of all worker and worklet types. Also, this contains the implementation of the [Web Workers API](https://html.spec.whatwg.org/C/#workers) (Dedicated Worker and Shared Worker) and [Worklets API](https://drafts.css-houdini.org/worklets/).
 
 # Worker / Worklet types
 
diff --git a/third_party/blink/renderer/core/workers/abstract_worker.h b/third_party/blink/renderer/core/workers/abstract_worker.h
index 12316ad24e637e..174a4430e7939a 100644
--- a/third_party/blink/renderer/core/workers/abstract_worker.h
+++ b/third_party/blink/renderer/core/workers/abstract_worker.h
@@ -46,7 +46,7 @@ class KURL;
 class ExecutionContext;
 
 // Implementation of the AbstractWorker interface defined in the WebWorker HTML
-// spec: https://html.spec.whatwg.org/multipage/workers.html#abstractworker
+// spec: https://html.spec.whatwg.org/C/#abstractworker
 class CORE_EXPORT AbstractWorker : public EventTargetWithInlineData,
                                    public ContextLifecycleObserver {
   USING_GARBAGE_COLLECTED_MIXIN(AbstractWorker);
diff --git a/third_party/blink/renderer/core/workers/dedicated_worker.cc b/third_party/blink/renderer/core/workers/dedicated_worker.cc
index dd4004ab879b22..be9ba2f0921d53 100644
--- a/third_party/blink/renderer/core/workers/dedicated_worker.cc
+++ b/third_party/blink/renderer/core/workers/dedicated_worker.cc
@@ -209,7 +209,7 @@ void DedicatedWorker::postMessage(ScriptState* script_state,
       std::move(transferable_message));
 }
 
-// https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+// https://html.spec.whatwg.org/C/#worker-processing-model
 void DedicatedWorker::Start() {
   DCHECK(GetExecutionContext()->IsContextThread());
 
diff --git a/third_party/blink/renderer/core/workers/dedicated_worker.h b/third_party/blink/renderer/core/workers/dedicated_worker.h
index e4336bd58e7149..90e97458f5c8cd 100644
--- a/third_party/blink/renderer/core/workers/dedicated_worker.h
+++ b/third_party/blink/renderer/core/workers/dedicated_worker.h
@@ -36,7 +36,7 @@ class WorkerClassicScriptLoader;
 class WorkerClients;
 
 // Implementation of the Worker interface defined in the WebWorker HTML spec:
-// https://html.spec.whatwg.org/multipage/workers.html#worker
+// https://html.spec.whatwg.org/C/#worker
 //
 // Confusingly, the Worker interface is for dedicated workers, so this class is
 // called DedicatedWorker. This lives on the thread that created the worker (the
diff --git a/third_party/blink/renderer/core/workers/dedicated_worker_global_scope.cc b/third_party/blink/renderer/core/workers/dedicated_worker_global_scope.cc
index b712a34cd427ec..0b5724d33f221e 100644
--- a/third_party/blink/renderer/core/workers/dedicated_worker_global_scope.cc
+++ b/third_party/blink/renderer/core/workers/dedicated_worker_global_scope.cc
@@ -65,7 +65,7 @@ const AtomicString& DedicatedWorkerGlobalScope::InterfaceName() const {
   return event_target_names::kDedicatedWorkerGlobalScope;
 }
 
-// https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+// https://html.spec.whatwg.org/C/#worker-processing-model
 void DedicatedWorkerGlobalScope::ImportModuleScript(
     const KURL& module_url_record,
     const FetchClientSettingsObjectSnapshot& outside_settings_object,
diff --git a/third_party/blink/renderer/core/workers/dedicated_worker_messaging_proxy.cc b/third_party/blink/renderer/core/workers/dedicated_worker_messaging_proxy.cc
index e2ce227167a7a9..0f5e97fae41335 100644
--- a/third_party/blink/renderer/core/workers/dedicated_worker_messaging_proxy.cc
+++ b/third_party/blink/renderer/core/workers/dedicated_worker_messaging_proxy.cc
@@ -179,7 +179,7 @@ void DedicatedWorkerMessagingProxy::DispatchErrorEvent(
   // "Thus, error reports propagate up to the chain of dedicated workers up to
   // the original Document, even if some of the workers along this chain have
   // been terminated and garbage collected."
-  // https://html.spec.whatwg.org/multipage/workers.html#runtime-script-errors-2
+  // https://html.spec.whatwg.org/C/#runtime-script-errors-2
   ErrorEvent* event =
       ErrorEvent::Create(error_message, location->Clone(), nullptr);
   if (worker_object_->DispatchEvent(*event) !=
@@ -194,7 +194,7 @@ void DedicatedWorkerMessagingProxy::DispatchErrorEvent(
 
   // The HTML spec requires to queue an error event using the DOM manipulation
   // task source.
-  // https://html.spec.whatwg.org/multipage/workers.html#runtime-script-errors-2
+  // https://html.spec.whatwg.org/C/#runtime-script-errors-2
   PostCrossThreadTask(
       *GetWorkerThread()->GetTaskRunner(TaskType::kDOMManipulation), FROM_HERE,
       CrossThreadBind(&DedicatedWorkerObjectProxy::ProcessUnhandledException,
diff --git a/third_party/blink/renderer/core/workers/global_scope_creation_params.h b/third_party/blink/renderer/core/workers/global_scope_creation_params.h
index af7ed99bf53923..6fd98dc9bd9fa2 100644
--- a/third_party/blink/renderer/core/workers/global_scope_creation_params.h
+++ b/third_party/blink/renderer/core/workers/global_scope_creation_params.h
@@ -67,7 +67,7 @@ struct CORE_EXPORT GlobalScopeCreationParams final {
   // The URL to be used as the worker global scope's URL.
   // According to the spec, this should be response URL of the top-level
   // worker script after the top-level worker script is loaded.
-  // https://html.spec.whatwg.org/multipage/workers.html#run-a-worker
+  // https://html.spec.whatwg.org/C/#run-a-worker
   //
   // However, this can't be set to response URL in case of module workers or
   // off-the-main-thread fetch, because at the time of GlobalScopeCreationParams
diff --git a/third_party/blink/renderer/core/workers/shared_worker_global_scope.cc b/third_party/blink/renderer/core/workers/shared_worker_global_scope.cc
index 1b54e91f574009..f95e37bf02a693 100644
--- a/third_party/blink/renderer/core/workers/shared_worker_global_scope.cc
+++ b/third_party/blink/renderer/core/workers/shared_worker_global_scope.cc
@@ -55,7 +55,7 @@ const AtomicString& SharedWorkerGlobalScope::InterfaceName() const {
   return event_target_names::kSharedWorkerGlobalScope;
 }
 
-// https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+// https://html.spec.whatwg.org/C/#worker-processing-model
 void SharedWorkerGlobalScope::ImportModuleScript(
     const KURL& module_url_record,
     const FetchClientSettingsObjectSnapshot& outside_settings_object,
diff --git a/third_party/blink/renderer/core/workers/shared_worker_reporting_proxy.cc b/third_party/blink/renderer/core/workers/shared_worker_reporting_proxy.cc
index 150cbc7736d0d1..3e7d6d928621ec 100644
--- a/third_party/blink/renderer/core/workers/shared_worker_reporting_proxy.cc
+++ b/third_party/blink/renderer/core/workers/shared_worker_reporting_proxy.cc
@@ -51,7 +51,7 @@ void SharedWorkerReportingProxy::ReportException(
   // spec:
   // "For shared workers, if the error is still not handled afterwards, the
   // error may be reported to a developer console."
-  // https://html.spec.whatwg.org/multipage/workers.html#runtime-script-errors-2
+  // https://html.spec.whatwg.org/C/#runtime-script-errors-2
 }
 
 void SharedWorkerReportingProxy::ReportConsoleMessage(MessageSource,
@@ -66,7 +66,7 @@ void SharedWorkerReportingProxy::DidFetchScript() {
   DCHECK(!IsMainThread());
   // TODO(nhiroki): Change the task type to kDOMManipulation here and elsewhere
   // in this file. See the HTML spec:
-  // https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model:dom-manipulation-task-source-2
+  // https://html.spec.whatwg.org/C/#worker-processing-model:dom-manipulation-task-source-2
   PostCrossThreadTask(
       *parent_execution_context_task_runners_->Get(TaskType::kInternalDefault),
       FROM_HERE,
diff --git a/third_party/blink/renderer/core/workers/worker_global_scope.cc b/third_party/blink/renderer/core/workers/worker_global_scope.cc
index be3c0542a67778..78a4ad76bc03bf 100644
--- a/third_party/blink/renderer/core/workers/worker_global_scope.cc
+++ b/third_party/blink/renderer/core/workers/worker_global_scope.cc
@@ -156,7 +156,7 @@ void WorkerGlobalScope::importScripts(
 }
 
 // Implementation of the "importScripts()" algorithm:
-// https://html.spec.whatwg.org/multipage/workers.html#dom-workerglobalscope-importscripts
+// https://html.spec.whatwg.org/C/#dom-workerglobalscope-importscripts
 void WorkerGlobalScope::importScriptsFromStrings(
     const Vector<String>& urls,
     ExceptionState& exception_state) {
@@ -355,7 +355,7 @@ void WorkerGlobalScope::EvaluateClassicScript(
     debugger->ExternalAsyncTaskFinished(stack_id);
 }
 
-// https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+// https://html.spec.whatwg.org/C/#worker-processing-model
 void WorkerGlobalScope::ImportClassicScript(
     const KURL& script_url,
     const FetchClientSettingsObjectSnapshot& outside_settings_object,
@@ -402,7 +402,7 @@ void WorkerGlobalScope::DidReceiveResponseForClassicScript(
   probe::didReceiveScriptResponse(this, classic_script_loader->Identifier());
 }
 
-// https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+// https://html.spec.whatwg.org/C/#worker-processing-model
 void WorkerGlobalScope::DidImportClassicScript(
     WorkerClassicScriptLoader* classic_script_loader,
     const v8_inspector::V8StackTraceId& stack_id) {
diff --git a/third_party/blink/renderer/core/workers/worker_global_scope.idl b/third_party/blink/renderer/core/workers/worker_global_scope.idl
index 38cfe8cd370937..ea15aa01b25a93 100644
--- a/third_party/blink/renderer/core/workers/worker_global_scope.idl
+++ b/third_party/blink/renderer/core/workers/worker_global_scope.idl
@@ -69,7 +69,7 @@
     void queueMicrotask(VoidFunction callback);
 
     // AnimationFrameProvider mixin
-    // https://html.spec.whatwg.org/multipage/imagebitmap-and-animations.html#animation-frames
+    // https://html.spec.whatwg.org/C/#animation-frames
     [RuntimeEnabled=OffscreenCanvas, RaisesException] long requestAnimationFrame(FrameRequestCallback callback);
     [RuntimeEnabled=OffscreenCanvas] void cancelAnimationFrame(long handle);
 
diff --git a/third_party/blink/renderer/core/workers/worker_module_tree_client.cc b/third_party/blink/renderer/core/workers/worker_module_tree_client.cc
index bbb7be37bc3d3c..1720640cc0f6e8 100644
--- a/third_party/blink/renderer/core/workers/worker_module_tree_client.cc
+++ b/third_party/blink/renderer/core/workers/worker_module_tree_client.cc
@@ -17,7 +17,7 @@ WorkerModuleTreeClient::WorkerModuleTreeClient(Modulator* modulator)
 
 // A partial implementation of the "Processing model" algorithm in the HTML
 // WebWorker spec:
-// https://html.spec.whatwg.org/multipage/workers.html#worker-processing-model
+// https://html.spec.whatwg.org/C/#worker-processing-model
 void WorkerModuleTreeClient::NotifyModuleTreeLoadFinished(
     ModuleScript* module_script) {
   auto* execution_context =
diff --git a/third_party/blink/renderer/core/workers/worker_options.idl b/third_party/blink/renderer/core/workers/worker_options.idl
index 238820038e67f5..e0af37955b872b 100644
--- a/third_party/blink/renderer/core/workers/worker_options.idl
+++ b/third_party/blink/renderer/core/workers/worker_options.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/workers.html#workeroptions
+// https://html.spec.whatwg.org/C/#workeroptions
 dictionary WorkerOptions {
     WorkerType type = "classic";
     RequestCredentials credentials = "same-origin";
diff --git a/third_party/blink/renderer/core/workers/worker_or_worklet_global_scope.cc b/third_party/blink/renderer/core/workers/worker_or_worklet_global_scope.cc
index 3572ab52dd1d48..055824a5d85d8d 100644
--- a/third_party/blink/renderer/core/workers/worker_or_worklet_global_scope.cc
+++ b/third_party/blink/renderer/core/workers/worker_or_worklet_global_scope.cc
@@ -235,7 +235,7 @@ void WorkerOrWorkletGlobalScope::BindContentSecurityPolicyToExecutionContext() {
 
 // Implementation of the "fetch a module worker script graph" algorithm in the
 // HTML spec:
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-worker-script-tree
+// https://html.spec.whatwg.org/C/#fetch-a-module-worker-script-tree
 void WorkerOrWorkletGlobalScope::FetchModuleScript(
     const KURL& module_url_record,
     const FetchClientSettingsObjectSnapshot& fetch_client_settings_object,
diff --git a/third_party/blink/renderer/core/workers/worklet_global_scope.h b/third_party/blink/renderer/core/workers/worklet_global_scope.h
index 9cd65bbf43c101..02a4aaf979bdd8 100644
--- a/third_party/blink/renderer/core/workers/worklet_global_scope.h
+++ b/third_party/blink/renderer/core/workers/worklet_global_scope.h
@@ -74,7 +74,7 @@ class CORE_EXPORT WorkletGlobalScope
 
   const base::UnguessableToken& GetAgentClusterID() const final {
     // Currently, worklet agents have no clearly defined owner. See
-    // https://html.spec.whatwg.org/multipage/webappapis.html#integration-with-the-javascript-agent-cluster-formalism
+    // https://html.spec.whatwg.org/C/#integration-with-the-javascript-agent-cluster-formalism
     //
     // However, it is intended that a SharedArrayBuffer can be shared with a
     // worklet, e.g. the AudioWorklet. If this WorkletGlobalScope's creation
diff --git a/third_party/blink/renderer/core/xml/parser/xml_document_parser.cc b/third_party/blink/renderer/core/xml/parser/xml_document_parser.cc
index 6ebfa142960c0c..b3b9ad2ba123fa 100644
--- a/third_party/blink/renderer/core/xml/parser/xml_document_parser.cc
+++ b/third_party/blink/renderer/core/xml/parser/xml_document_parser.cc
@@ -766,7 +766,7 @@ XMLDocumentParser::XMLDocumentParser(DocumentFragment* fragment,
       script_start_position_(TextPosition::BelowRangePosition()),
       parsing_fragment_(true) {
   // Step 2 of
-  // https://html.spec.whatwg.org/multipage/xhtml.html#xml-fragment-parsing-algorithm
+  // https://html.spec.whatwg.org/C/#xml-fragment-parsing-algorithm
   // The following code collects prefix-namespace mapping in scope on
   // |parent_element|.
   HeapVector<Member<Element>> elem_stack;
@@ -1463,7 +1463,7 @@ static void ExternalSubsetHandler(void* closure,
                                   const xmlChar*,
                                   const xmlChar* external_id,
                                   const xmlChar*) {
-  // https://html.spec.whatwg.org/multipage/xhtml.html#parsing-xhtml-documents:named-character-references
+  // https://html.spec.whatwg.org/C/#parsing-xhtml-documents:named-character-references
   String ext_id = ToString(external_id);
   if (ext_id == "-//W3C//DTD XHTML 1.0 Transitional//EN" ||
       ext_id == "-//W3C//DTD XHTML 1.1//EN" ||
diff --git a/third_party/blink/renderer/devtools/front_end/elements/ElementsTreeElement.js b/third_party/blink/renderer/devtools/front_end/elements/ElementsTreeElement.js
index 4ead19d47b12c7..c304d00d5b909b 100644
--- a/third_party/blink/renderer/devtools/front_end/elements/ElementsTreeElement.js
+++ b/third_party/blink/renderer/devtools/front_end/elements/ElementsTreeElement.js
@@ -1325,7 +1325,7 @@ Elements.ElementsTreeElement = class extends UI.TreeElement {
       //     `indexOfSpace - 1` as a URL and repeat step 1).
       // 2b) Else, collect the preceding characters as a URL.
       // 3) Collect the characters from `indexOfSpace` up to the next comma as the size descriptor and repeat step 1).
-      // https://html.spec.whatwg.org/multipage/embedded-content.html#parse-a-srcset-attribute
+      // https://html.spec.whatwg.org/C/#parse-a-srcset-attribute
       const fragment = createDocumentFragment();
       let i = 0;
       while (value.length) {
diff --git a/third_party/blink/renderer/modules/accessibility/ax_layout_object.cc b/third_party/blink/renderer/modules/accessibility/ax_layout_object.cc
index 3bad59acb3df0e..5024418234c6bd 100644
--- a/third_party/blink/renderer/modules/accessibility/ax_layout_object.cc
+++ b/third_party/blink/renderer/modules/accessibility/ax_layout_object.cc
@@ -1508,7 +1508,7 @@ String AXLayoutObject::StringValue() const {
   // time controls, by returning their value converted to text, with the
   // exception of checkboxes and radio buttons (which would return "on"), and
   // buttons which will return their name.
-  // https://html.spec.whatwg.org/multipage/forms.html#dom-input-value
+  // https://html.spec.whatwg.org/C/#dom-input-value
   if (const auto* input = ToHTMLInputElementOrNull(GetNode())) {
     if (input->type() != input_type_names::kButton &&
         input->type() != input_type_names::kCheckbox &&
@@ -2199,7 +2199,7 @@ AtomicString AXLayoutObject::Language() const {
   // The style engine relies on, for example, the "lang" attribute of the
   // current node and its ancestors, and the document's "content-language"
   // header. See the Language of a Node Spec at
-  // https://html.spec.whatwg.org/multipage/dom.html#language
+  // https://html.spec.whatwg.org/C/#language
 
   if (!GetLayoutObject())
     return AXNodeObject::Language();
diff --git a/third_party/blink/renderer/modules/accessibility/ax_node_object.cc b/third_party/blink/renderer/modules/accessibility/ax_node_object.cc
index 0ff9e44c6532f5..f648104b15a0c9 100644
--- a/third_party/blink/renderer/modules/accessibility/ax_node_object.cc
+++ b/third_party/blink/renderer/modules/accessibility/ax_node_object.cc
@@ -1626,7 +1626,7 @@ String AXNodeObject::StringValue() const {
   // time controls, by returning their value converted to text, with the
   // exception of checkboxes and radio buttons (which would return "on"), and
   // buttons which will return their name.
-  // https://html.spec.whatwg.org/multipage/forms.html#dom-input-value
+  // https://html.spec.whatwg.org/C/#dom-input-value
   if (const auto* input = ToHTMLInputElementOrNull(node)) {
     if (input->type() != input_type_names::kButton &&
         input->type() != input_type_names::kCheckbox &&
diff --git a/third_party/blink/renderer/modules/broadcastchannel/broadcast_channel.idl b/third_party/blink/renderer/modules/broadcastchannel/broadcast_channel.idl
index 2aeb115f7e5d89..83ca9a2a223988 100644
--- a/third_party/blink/renderer/modules/broadcastchannel/broadcast_channel.idl
+++ b/third_party/blink/renderer/modules/broadcastchannel/broadcast_channel.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/comms.html#broadcastchannel
+// https://html.spec.whatwg.org/C/#broadcastchannel
 
 [
     Constructor(DOMString name),
diff --git a/third_party/blink/renderer/modules/canvas/README.md b/third_party/blink/renderer/modules/canvas/README.md
index 64546adb1305d8..e791d1561cae1c 100644
--- a/third_party/blink/renderer/modules/canvas/README.md
+++ b/third_party/blink/renderer/modules/canvas/README.md
@@ -50,10 +50,10 @@ rendering context API. Used by `CanvasRenderingContext2D`,
 
 ### Final classes
 
-`CanvasRenderingContext2D` - 2D context for HTML Canvas element. [[spec](https://html.spec.whatwg.org/multipage/scripting.html#2dcontext)]
+`CanvasRenderingContext2D` - 2D context for HTML Canvas element. [[spec](https://html.spec.whatwg.org/C/#2dcontext)]
 
 `OffscreenCanvasRenderingContext2D` - 2D context for OffscreenCanvas.
-[[spec](https://html.spec.whatwg.org/multipage/scripting.html#the-offscreen-2d-rendering-context)]
+[[spec](https://html.spec.whatwg.org/C/#the-offscreen-2d-rendering-context)]
 
 `WebGLRenderingContext` - WebGL context for both HTML and Offscreen canvas.
 [[spec](https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14)]
@@ -62,7 +62,7 @@ rendering context API. Used by `CanvasRenderingContext2D`,
 [[spec](https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7)]
 
 `ImageBitmapRenderingContext` - The rendering context provided by `ImageBitmap`.
-[[spec](https://html.spec.whatwg.org/multipage/scripting.html#the-imagebitmap-rendering-context)]
+[[spec](https://html.spec.whatwg.org/C/#the-imagebitmap-rendering-context)]
 
 `PaintRenderingContext2D` - Rendering context for CSS Painting.
 [[spec](https://www.w3.org/TR/css-paint-api-1/)]
diff --git a/third_party/blink/renderer/modules/canvas/canvas2d/canvas_path.idl b/third_party/blink/renderer/modules/canvas/canvas2d/canvas_path.idl
index 2a7f93fca5f2de..29bfbaf5b1be66 100644
--- a/third_party/blink/renderer/modules/canvas/canvas2d/canvas_path.idl
+++ b/third_party/blink/renderer/modules/canvas/canvas2d/canvas_path.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/scripting.html#canvaspath
+// https://html.spec.whatwg.org/C/#canvaspath
 
 [
     NoInterfaceObject // Always used on target of 'implements'
diff --git a/third_party/blink/renderer/modules/canvas/canvas2d/canvas_rendering_context_2d.idl b/third_party/blink/renderer/modules/canvas/canvas2d/canvas_rendering_context_2d.idl
index b8f1ecd9a8abb5..840302c2b1d5f1 100644
--- a/third_party/blink/renderer/modules/canvas/canvas2d/canvas_rendering_context_2d.idl
+++ b/third_party/blink/renderer/modules/canvas/canvas2d/canvas_rendering_context_2d.idl
@@ -23,7 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/canvas.html#canvasrenderingcontext2d
+// https://html.spec.whatwg.org/C/#canvasrenderingcontext2d
 
 // The spec specifies:
 //    typedef (HTMLImageElement or
diff --git a/third_party/blink/renderer/modules/canvas/canvas2d/hit_region_options.idl b/third_party/blink/renderer/modules/canvas/canvas2d/hit_region_options.idl
index 6146304012fb12..46c738e158fe5d 100644
--- a/third_party/blink/renderer/modules/canvas/canvas2d/hit_region_options.idl
+++ b/third_party/blink/renderer/modules/canvas/canvas2d/hit_region_options.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Spec: https://html.spec.whatwg.org/multipage/scripting.html#hitregionoptions
+// Spec: https://html.spec.whatwg.org/C/#hitregionoptions
 
 dictionary HitRegionOptions {
     Path2D? path = null;
diff --git a/third_party/blink/renderer/modules/canvas/imagebitmap/image_bitmap_rendering_context.idl b/third_party/blink/renderer/modules/canvas/imagebitmap/image_bitmap_rendering_context.idl
index ef721dd47ac284..f90843824251e1 100644
--- a/third_party/blink/renderer/modules/canvas/imagebitmap/image_bitmap_rendering_context.idl
+++ b/third_party/blink/renderer/modules/canvas/imagebitmap/image_bitmap_rendering_context.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/scripting.html#the-imagebitmap-rendering-context
+// https://html.spec.whatwg.org/C/#the-imagebitmap-rendering-context
 
 interface ImageBitmapRenderingContext {
     // back-reference to the canvas
diff --git a/third_party/blink/renderer/modules/canvas/offscreencanvas/offscreen_canvas_module.idl b/third_party/blink/renderer/modules/canvas/offscreencanvas/offscreen_canvas_module.idl
index 496e2282b1b349..3e312d58f57613 100644
--- a/third_party/blink/renderer/modules/canvas/offscreencanvas/offscreen_canvas_module.idl
+++ b/third_party/blink/renderer/modules/canvas/offscreencanvas/offscreen_canvas_module.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/scripting.html#the-offscreencanvas-interface
+// https://html.spec.whatwg.org/C/#the-offscreencanvas-interface
 
 typedef (OffscreenCanvasRenderingContext2D or
          WebGLRenderingContext or
diff --git a/third_party/blink/renderer/modules/canvas/offscreencanvas/offscreen_canvas_module_support_webgl2_compute.idl b/third_party/blink/renderer/modules/canvas/offscreencanvas/offscreen_canvas_module_support_webgl2_compute.idl
index cc953b878868bc..d4ed9dd5dbdb23 100644
--- a/third_party/blink/renderer/modules/canvas/offscreencanvas/offscreen_canvas_module_support_webgl2_compute.idl
+++ b/third_party/blink/renderer/modules/canvas/offscreencanvas/offscreen_canvas_module_support_webgl2_compute.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/scripting.html#the-offscreencanvas-interface
+// https://html.spec.whatwg.org/C/#the-offscreencanvas-interface
 
 typedef (OffscreenCanvasRenderingContext2D or
          WebGLRenderingContext or
diff --git a/third_party/blink/renderer/modules/canvas/offscreencanvas2d/offscreen_canvas_rendering_context_2d.idl b/third_party/blink/renderer/modules/canvas/offscreencanvas2d/offscreen_canvas_rendering_context_2d.idl
index b53ed13ec6ddab..416eb4cbb6a544 100644
--- a/third_party/blink/renderer/modules/canvas/offscreencanvas2d/offscreen_canvas_rendering_context_2d.idl
+++ b/third_party/blink/renderer/modules/canvas/offscreencanvas2d/offscreen_canvas_rendering_context_2d.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/scripting.html#the-offscreen-2d-rendering-context
+// https://html.spec.whatwg.org/C/#the-offscreen-2d-rendering-context
 
 [
     Exposed=(Window,Worker),
diff --git a/third_party/blink/renderer/modules/credentialmanager/password_credential.cc b/third_party/blink/renderer/modules/credentialmanager/password_credential.cc
index a06539b5e815b7..73e76953ca8dd7 100644
--- a/third_party/blink/renderer/modules/credentialmanager/password_credential.cc
+++ b/third_party/blink/renderer/modules/credentialmanager/password_credential.cc
@@ -49,7 +49,7 @@ PasswordCredential* PasswordCredential::Create(
   for (ListedElement* submittable_element : form->ListedElements()) {
     // The "form data set" contains an entry for a |submittable_element| only if
     // it has a non-empty `name` attribute.
-    // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#constructing-the-form-data-set
+    // https://html.spec.whatwg.org/C/#constructing-the-form-data-set
     DCHECK(!submittable_element->GetName().IsEmpty());
 
     FileOrUSVString value;
diff --git a/third_party/blink/renderer/modules/eventsource/event_source.idl b/third_party/blink/renderer/modules/eventsource/event_source.idl
index 4058f95899a234..900568acde13e8 100644
--- a/third_party/blink/renderer/modules/eventsource/event_source.idl
+++ b/third_party/blink/renderer/modules/eventsource/event_source.idl
@@ -29,7 +29,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/comms.html#the-eventsource-interface
+// https://html.spec.whatwg.org/C/#the-eventsource-interface
 
 [
     ActiveScriptWrappable,
diff --git a/third_party/blink/renderer/modules/eventsource/event_source_init.idl b/third_party/blink/renderer/modules/eventsource/event_source_init.idl
index f4594e8f47a549..88733e7707a817 100644
--- a/third_party/blink/renderer/modules/eventsource/event_source_init.idl
+++ b/third_party/blink/renderer/modules/eventsource/event_source_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/comms.html#the-eventsource-interface
+// https://html.spec.whatwg.org/C/#the-eventsource-interface
 
 dictionary EventSourceInit {
     boolean withCredentials = false;
diff --git a/third_party/blink/renderer/modules/indexeddb/docs/idb_data_path.md b/third_party/blink/renderer/modules/indexeddb/docs/idb_data_path.md
index b19a7f5b9bb9ad..9cf858891c7a1e 100644
--- a/third_party/blink/renderer/modules/indexeddb/docs/idb_data_path.md
+++ b/third_party/blink/renderer/modules/indexeddb/docs/idb_data_path.md
@@ -39,7 +39,7 @@ The backing store implementation is built on top of two storage systems:
 
 Storing a JavaScript value in IndexedDB is specified at a high level in the
 [HTML Structured Data
-Specification](https://html.spec.whatwg.org/multipage/structured-data.html#serializable-objects).
+Specification](https://html.spec.whatwg.org/C/#serializable-objects).
 Blink's implementation of the specification is responsible for converting
 between [V8](https://developers.google.com/v8/) values and the byte sequences in
 IndexedDB's backing store. The implementation is in `SerializedScriptValue`
diff --git a/third_party/blink/renderer/modules/indexeddb/docs/idb_overview.md b/third_party/blink/renderer/modules/indexeddb/docs/idb_overview.md
index c03e93f1412fd1..de5f03557ad8c6 100644
--- a/third_party/blink/renderer/modules/indexeddb/docs/idb_overview.md
+++ b/third_party/blink/renderer/modules/indexeddb/docs/idb_overview.md
@@ -39,7 +39,7 @@ entries with the same primary key - *multiEntry* indexes map each element inside
 an IDB value array to an index entry.
 
 IDB *values* are [a fairly large subset of JavaScript's supported
-types](https://html.spec.whatwg.org/multipage/structured-data.html#serializable-objects).
+types](https://html.spec.whatwg.org/C/#serializable-objects).
 There are no object store-level constraints on value types, so the values in a
 store can be pretty heterogeneous. By contrast, SQL tables have schemas which
 heavily constrain the rows.
diff --git a/third_party/blink/renderer/modules/navigatorcontentutils/navigator_content_utils.idl b/third_party/blink/renderer/modules/navigatorcontentutils/navigator_content_utils.idl
index e36c9b8bed7726..d36a5f4b742fb2 100644
--- a/third_party/blink/renderer/modules/navigatorcontentutils/navigator_content_utils.idl
+++ b/third_party/blink/renderer/modules/navigatorcontentutils/navigator_content_utils.idl
@@ -18,7 +18,7 @@
     Boston, MA 02110-1301, USA.
 */
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#custom-handlers
+// https://html.spec.whatwg.org/C/#custom-handlers
 
 [
     ImplementedAs=NavigatorContentUtils
diff --git a/third_party/blink/renderer/modules/plugins/navigator_plugins.idl b/third_party/blink/renderer/modules/plugins/navigator_plugins.idl
index 767905efa34978..8f7653c109cdd3 100644
--- a/third_party/blink/renderer/modules/plugins/navigator_plugins.idl
+++ b/third_party/blink/renderer/modules/plugins/navigator_plugins.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#navigatorplugins
+// https://html.spec.whatwg.org/C/#navigatorplugins
 [
     ImplementedAs=NavigatorPlugins
 ] partial interface Navigator {
diff --git a/third_party/blink/renderer/modules/plugins/plugin.idl b/third_party/blink/renderer/modules/plugins/plugin.idl
index 2a8136cd4dfa29..2a1be74df76326 100644
--- a/third_party/blink/renderer/modules/plugins/plugin.idl
+++ b/third_party/blink/renderer/modules/plugins/plugin.idl
@@ -18,7 +18,7 @@
     Boston, MA 02110-1301, USA.
 */
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#plugins-2
+// https://html.spec.whatwg.org/C/#plugins-2
 
 [
     ImplementedAs=DOMPlugin,
diff --git a/third_party/blink/renderer/modules/plugins/plugin_array.idl b/third_party/blink/renderer/modules/plugins/plugin_array.idl
index f7d7a438b30f3a..9e123be58348c7 100644
--- a/third_party/blink/renderer/modules/plugins/plugin_array.idl
+++ b/third_party/blink/renderer/modules/plugins/plugin_array.idl
@@ -18,7 +18,7 @@
     Boston, MA 02110-1301, USA.
 */
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#plugins-2
+// https://html.spec.whatwg.org/C/#plugins-2
 
 [
     ImplementedAs=DOMPluginArray,
diff --git a/third_party/blink/renderer/modules/service_worker/service_worker_container.cc b/third_party/blink/renderer/modules/service_worker/service_worker_container.cc
index b22acfca06c564..f60082eaecee48 100644
--- a/third_party/blink/renderer/modules/service_worker/service_worker_container.cc
+++ b/third_party/blink/renderer/modules/service_worker/service_worker_container.cc
@@ -520,7 +520,7 @@ void ServiceWorkerContainer::ReceiveMessage(WebServiceWorkerObjectInfo source,
     if (!HasFiredDomContentLoaded(*document)) {
       // Wait for DOMContentLoaded. This corresponds to the specification steps
       // for "Parsing HTML documents": "The end" at
-      // https://html.spec.whatwg.org/multipage/parsing.html#the-end:
+      // https://html.spec.whatwg.org/C/#the-end:
       //
       // 1. Fire an event named DOMContentLoaded at the Document object, with
       // its bubbles attribute initialized to true.
diff --git a/third_party/blink/renderer/modules/srcobject/html_media_element_src_object.idl b/third_party/blink/renderer/modules/srcobject/html_media_element_src_object.idl
index 501bf865b11c8f..0481d3b37b75a7 100644
--- a/third_party/blink/renderer/modules/srcobject/html_media_element_src_object.idl
+++ b/third_party/blink/renderer/modules/srcobject/html_media_element_src_object.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/embedded-content.html#dom-media-srcobject
+// https://html.spec.whatwg.org/C/#dom-media-srcobject
 
 // TODO(guidou): Add support for MediaSource and Blob, as defined in the spec.
 typedef MediaStream MediaProvider;
diff --git a/third_party/blink/renderer/modules/storage/storage.idl b/third_party/blink/renderer/modules/storage/storage.idl
index 3a5e7f455cc81d..385a8d9b7119e9 100644
--- a/third_party/blink/renderer/modules/storage/storage.idl
+++ b/third_party/blink/renderer/modules/storage/storage.idl
@@ -23,7 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/webstorage.html#the-storage-interface
+// https://html.spec.whatwg.org/C/#the-storage-interface
 
 [ImplementedAs=StorageArea]
 interface Storage {
diff --git a/third_party/blink/renderer/modules/storage/storage_event.idl b/third_party/blink/renderer/modules/storage/storage_event.idl
index e6cc1512d7f4d4..0414d23f5817c4 100644
--- a/third_party/blink/renderer/modules/storage/storage_event.idl
+++ b/third_party/blink/renderer/modules/storage/storage_event.idl
@@ -23,7 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/webstorage.html#the-storageevent-interface
+// https://html.spec.whatwg.org/C/#the-storageevent-interface
 
 [
     Exposed=Window,
diff --git a/third_party/blink/renderer/modules/storage/storage_event_init.idl b/third_party/blink/renderer/modules/storage/storage_event_init.idl
index 72de6466229f4a..05a6a770e7c4cf 100644
--- a/third_party/blink/renderer/modules/storage/storage_event_init.idl
+++ b/third_party/blink/renderer/modules/storage/storage_event_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/webstorage.html#the-storageevent-interface
+// https://html.spec.whatwg.org/C/#the-storageevent-interface
 
 dictionary StorageEventInit : EventInit {
     DOMString? key;
diff --git a/third_party/blink/renderer/modules/websockets/close_event.idl b/third_party/blink/renderer/modules/websockets/close_event.idl
index a9d727d5b0a836..438a0b69cc2dcc 100644
--- a/third_party/blink/renderer/modules/websockets/close_event.idl
+++ b/third_party/blink/renderer/modules/websockets/close_event.idl
@@ -28,7 +28,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/comms.html#the-closeevent-interfaces
+// https://html.spec.whatwg.org/C/#the-closeevent-interfaces
 
 [
     Constructor(DOMString type, optional CloseEventInit eventInitDict),
diff --git a/third_party/blink/renderer/modules/websockets/close_event_init.idl b/third_party/blink/renderer/modules/websockets/close_event_init.idl
index ff5c9e8c5f3d94..47b2ba37f7ba83 100644
--- a/third_party/blink/renderer/modules/websockets/close_event_init.idl
+++ b/third_party/blink/renderer/modules/websockets/close_event_init.idl
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://html.spec.whatwg.org/multipage/comms.html#the-closeevent-interfaces
+// https://html.spec.whatwg.org/C/#the-closeevent-interfaces
 
 dictionary CloseEventInit : EventInit {
     boolean wasClean;
diff --git a/third_party/blink/renderer/modules/websockets/websocket.idl b/third_party/blink/renderer/modules/websockets/websocket.idl
index d979eb179ced7b..3c46ef69522870 100644
--- a/third_party/blink/renderer/modules/websockets/websocket.idl
+++ b/third_party/blink/renderer/modules/websockets/websocket.idl
@@ -29,7 +29,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/multipage/comms.html#the-websocket-interface
+// https://html.spec.whatwg.org/C/#the-websocket-interface
 
 enum BinaryType { "blob", "arraybuffer" };
 
diff --git a/third_party/blink/renderer/platform/fonts/LocaleInFonts.md b/third_party/blink/renderer/platform/fonts/LocaleInFonts.md
index 3696adffad3a83..0f5747cf15dc00 100644
--- a/third_party/blink/renderer/platform/fonts/LocaleInFonts.md
+++ b/third_party/blink/renderer/platform/fonts/LocaleInFonts.md
@@ -31,10 +31,10 @@ Note that `ComputedStyle::locale()` is an `AtomicString`
 for the style system to work without special casing,
 while `FontDescription::locale()` is a pointer to `LayoutLocale`.
 
-[lang attribute]: https://html.spec.whatwg.org/multipage/dom.html#the-lang-and-xml:lang-attributes
+[lang attribute]: https://html.spec.whatwg.org/C/#the-lang-and-xml:lang-attributes
 [BCP 47]: https://tools.ietf.org/html/bcp47
-[language of a node]: https://html.spec.whatwg.org/multipage/dom.html#language
-[content-language]: https://html.spec.whatwg.org/multipage/semantics.html#pragma-set-default-language
+[language of a node]: https://html.spec.whatwg.org/C/#language
+[content-language]: https://html.spec.whatwg.org/C/#pragma-set-default-language
 
 ## Generic Family
 
diff --git a/third_party/blink/renderer/platform/graphics/skia/skia_utils.h b/third_party/blink/renderer/platform/graphics/skia/skia_utils.h
index 7155983ee65d54..8155a31cf844e6 100644
--- a/third_party/blink/renderer/platform/graphics/skia/skia_utils.h
+++ b/third_party/blink/renderer/platform/graphics/skia/skia_utils.h
@@ -135,7 +135,7 @@ inline float BlurRadiusToStdDev(float radius) {
 
   // Per spec, sigma is exactly half the blur radius:
   // https://www.w3.org/TR/css-backgrounds-3/#shadow-blur
-  // https://html.spec.whatwg.org/multipage/canvas.html#when-shadows-are-drawn
+  // https://html.spec.whatwg.org/C/#when-shadows-are-drawn
   return radius * 0.5f;
 }
 
diff --git a/third_party/blink/renderer/platform/loader/fetch/fetch_client_settings_object.h b/third_party/blink/renderer/platform/loader/fetch/fetch_client_settings_object.h
index d963ba3f783d67..f6a5b7412a63f0 100644
--- a/third_party/blink/renderer/platform/loader/fetch/fetch_client_settings_object.h
+++ b/third_party/blink/renderer/platform/loader/fetch/fetch_client_settings_object.h
@@ -21,13 +21,13 @@ namespace blink {
 
 // This is a partial interface of the "settings object" concept defined in the
 // HTML spec:
-// https://html.spec.whatwg.org/multipage/webappapis.html#settings-object
+// https://html.spec.whatwg.org/C/#settings-object
 //
 // This is also a partial interface of the "fetch client settings object" used
 // in module script fetch. Other part of the "fetch client settings object" is
 // currently implemented by ResourceFetcher and FetchContext, and this class is
 // used together with them.
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-worker-script-tree
+// https://html.spec.whatwg.org/C/#fetch-a-module-worker-script-tree
 class PLATFORM_EXPORT FetchClientSettingsObject
     : public GarbageCollectedFinalized<FetchClientSettingsObject> {
  public:
@@ -35,23 +35,23 @@ class PLATFORM_EXPORT FetchClientSettingsObject
 
   // "A URL used by APIs called by scripts that use this environment settings
   // object to parse URLs."
-  // https://html.spec.whatwg.org/multipage/webappapis.html#api-base-url
+  // https://html.spec.whatwg.org/C/#api-base-url
   virtual const KURL& BaseURL() const = 0;
 
   // "An origin used in security checks."
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-settings-object-origin
+  // https://html.spec.whatwg.org/C/#concept-settings-object-origin
   virtual const SecurityOrigin* GetSecurityOrigin() const = 0;
 
   // "The default referrer policy for fetches performed using this environment
   // settings object as a request client."
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-settings-object-referrer-policy
+  // https://html.spec.whatwg.org/C/#concept-settings-object-referrer-policy
   virtual network::mojom::ReferrerPolicy GetReferrerPolicy() const = 0;
 
   // "referrerURL" used in the "Determine request's Referrer" algorithm:
   // https://w3c.github.io/webappsec-referrer-policy/#determine-requests-referrer
   virtual const String GetOutgoingReferrer() const = 0;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#https-state
+  // https://html.spec.whatwg.org/C/#https-state
   virtual HttpsState GetHttpsState() const = 0;
 
   // Used for classic top-level scripts and importScripts().
diff --git a/third_party/blink/renderer/platform/loader/fetch/fetch_client_settings_object_snapshot.h b/third_party/blink/renderer/platform/loader/fetch/fetch_client_settings_object_snapshot.h
index 3989e7c2ac52b5..3e900b8bb04595 100644
--- a/third_party/blink/renderer/platform/loader/fetch/fetch_client_settings_object_snapshot.h
+++ b/third_party/blink/renderer/platform/loader/fetch/fetch_client_settings_object_snapshot.h
@@ -58,8 +58,8 @@ struct CrossThreadFetchClientSettingsObjectData {
 // instance of this class can be passed to another thread without cross-thread
 // synchronization. Don't keep this object persistently, instead create a new
 // instance per each "fetch a module script graph" algorithm:
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-script-tree
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-worker-script-tree
+// https://html.spec.whatwg.org/C/#fetch-a-module-script-tree
+// https://html.spec.whatwg.org/C/#fetch-a-module-worker-script-tree
 //
 // This class should be used only for main worker (worklet) script loading. For
 // other resources, FetchClientSettingsObjectImpl should be used. See the class
diff --git a/third_party/blink/renderer/platform/loader/fetch/resource_loader_options.h b/third_party/blink/renderer/platform/loader/fetch/resource_loader_options.h
index 07983d1fbb347d..c20c349d24b61b 100644
--- a/third_party/blink/renderer/platform/loader/fetch/resource_loader_options.h
+++ b/third_party/blink/renderer/platform/loader/fetch/resource_loader_options.h
@@ -65,7 +65,7 @@ enum CorsHandlingByResourceFetcher {
 };
 
 // Was the request generated from a "parser-inserted" element?
-// https://html.spec.whatwg.org/multipage/scripting.html#parser-inserted
+// https://html.spec.whatwg.org/C/#parser-inserted
 enum ParserDisposition : uint8_t { kParserInserted, kNotParserInserted };
 
 enum CacheAwareLoadingEnabled : uint8_t {
diff --git a/third_party/blink/renderer/platform/loader/fetch/script_fetch_options.cc b/third_party/blink/renderer/platform/loader/fetch/script_fetch_options.cc
index 7391ff2384023e..f5aebce896414d 100644
--- a/third_party/blink/renderer/platform/loader/fetch/script_fetch_options.cc
+++ b/third_party/blink/renderer/platform/loader/fetch/script_fetch_options.cc
@@ -9,7 +9,7 @@
 
 namespace blink {
 
-// https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-classic-script
+// https://html.spec.whatwg.org/C/#fetch-a-classic-script
 FetchParameters ScriptFetchOptions::CreateFetchParameters(
     const KURL& url,
     const SecurityOrigin* security_origin,
@@ -36,7 +36,7 @@ FetchParameters ScriptFetchOptions::CreateFetchParameters(
   // Step 3. Set up the classic script request given request and options. [spec
   // text]
   //
-  // https://html.spec.whatwg.org/multipage/webappapis.html#set-up-the-classic-script-request
+  // https://html.spec.whatwg.org/C/#set-up-the-classic-script-request
   // Set request's cryptographic nonce metadata to options's cryptographic
   // nonce, [spec text]
   params.SetContentSecurityPolicyNonce(Nonce());
diff --git a/third_party/blink/renderer/platform/loader/fetch/script_fetch_options.h b/third_party/blink/renderer/platform/loader/fetch/script_fetch_options.h
index f5413347ede50b..eb620cc3294f78 100644
--- a/third_party/blink/renderer/platform/loader/fetch/script_fetch_options.h
+++ b/third_party/blink/renderer/platform/loader/fetch/script_fetch_options.h
@@ -21,10 +21,10 @@ class KURL;
 class SecurityOrigin;
 
 // ScriptFetchOptions corresponds to the spec concept "script fetch options".
-// https://html.spec.whatwg.org/multipage/webappapis.html#script-fetch-options
+// https://html.spec.whatwg.org/C/#script-fetch-options
 class PLATFORM_EXPORT ScriptFetchOptions final {
  public:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#default-classic-script-fetch-options
+  // https://html.spec.whatwg.org/C/#default-classic-script-fetch-options
   // "The default classic script fetch options are a script fetch options whose
   // cryptographic nonce is the empty string, integrity metadata is the empty
   // string, parser metadata is "not-parser-inserted", and credentials mode
@@ -70,7 +70,7 @@ class PLATFORM_EXPORT ScriptFetchOptions final {
   }
   mojom::FetchImportanceMode Importance() const { return importance_; }
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-classic-script
+  // https://html.spec.whatwg.org/C/#fetch-a-classic-script
   // Steps 1 and 3.
   FetchParameters CreateFetchParameters(const KURL&,
                                         const SecurityOrigin*,
@@ -79,20 +79,20 @@ class PLATFORM_EXPORT ScriptFetchOptions final {
                                         FetchParameters::DeferOption) const;
 
  private:
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-fetch-options-nonce
+  // https://html.spec.whatwg.org/C/#concept-script-fetch-options-nonce
   const String nonce_;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-fetch-options-integrity
+  // https://html.spec.whatwg.org/C/#concept-script-fetch-options-integrity
   const IntegrityMetadataSet integrity_metadata_;
   const String integrity_attribute_;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-fetch-options-parser
+  // https://html.spec.whatwg.org/C/#concept-script-fetch-options-parser
   const ParserDisposition parser_state_;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-fetch-options-credentials
+  // https://html.spec.whatwg.org/C/#concept-script-fetch-options-credentials
   const network::mojom::FetchCredentialsMode credentials_mode_;
 
-  // https://html.spec.whatwg.org/multipage/webappapis.html#concept-script-fetch-options-referrer-policy
+  // https://html.spec.whatwg.org/C/#concept-script-fetch-options-referrer-policy
   const network::mojom::ReferrerPolicy referrer_policy_;
 
   // Priority Hints and a request's "importance" mode are currently
diff --git a/third_party/blink/renderer/platform/network/form_data_encoder.cc b/third_party/blink/renderer/platform/network/form_data_encoder.cc
index c5cca2a72888af..cf29b47a23848e 100644
--- a/third_party/blink/renderer/platform/network/form_data_encoder.cc
+++ b/third_party/blink/renderer/platform/network/form_data_encoder.cc
@@ -180,7 +180,7 @@ void FormDataEncoder::AddFilenameToMultiPartHeader(
   //
   // See also:
   //
-  // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#multipart-form-data
+  // https://html.spec.whatwg.org/C/#multipart-form-data
   // https://www.chromestatus.com/features/5634575908732928
   // https://crbug.com/661819
   // https://encoding.spec.whatwg.org/#concept-encoding-process
diff --git a/third_party/blink/renderer/platform/network/http_parsers.cc b/third_party/blink/renderer/platform/network/http_parsers.cc
index 9847f064c20711..b064ed9fab4844 100644
--- a/third_party/blink/renderer/platform/network/http_parsers.cc
+++ b/third_party/blink/renderer/platform/network/http_parsers.cc
@@ -146,7 +146,7 @@ bool IsContentDispositionAttachment(const String& content_disposition) {
   return net::HttpContentDisposition(string, std::string()).is_attachment();
 }
 
-// https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-refresh
+// https://html.spec.whatwg.org/C/#attr-meta-http-equiv-refresh
 bool ParseHTTPRefresh(const String& refresh,
                       WTF::CharacterMatchFunctionPtr matcher,
                       double& delay,
diff --git a/third_party/blink/renderer/platform/scheduler/TaskSchedulingInBlink.md b/third_party/blink/renderer/platform/scheduler/TaskSchedulingInBlink.md
index c46763c15eff44..3003f5a20d1235 100644
--- a/third_party/blink/renderer/platform/scheduler/TaskSchedulingInBlink.md
+++ b/third_party/blink/renderer/platform/scheduler/TaskSchedulingInBlink.md
@@ -84,7 +84,7 @@ TaskType is a required parameter of all GetTaskRunner() methods and FrameSchedul
 returns an appropriate task runner based on the TaskType.
 
 All tasks mentioned in the spec should have task source explicitly defined
-(e.g. see [generic task sources definition](https://html.spec.whatwg.org/multipage/webappapis.html#generic-task-sources)
+(e.g. see [generic task sources definition](https://html.spec.whatwg.org/C/#generic-task-sources)
 in the spec). There are still some places where the task source is not mentioned
 explicitly — reach out to domenic@ and garykac@ for advice.
 
diff --git a/third_party/blink/renderer/platform/text/character.h b/third_party/blink/renderer/platform/text/character.h
index f7d27b48355716..ef8b1faddef1da 100644
--- a/third_party/blink/renderer/platform/text/character.h
+++ b/third_party/blink/renderer/platform/text/character.h
@@ -100,7 +100,7 @@ class PLATFORM_EXPORT Character {
 
   static bool IsUprightInMixedVertical(UChar32 character);
 
-  // https://html.spec.whatwg.org/multipage/scripting.html#prod-potentialcustomelementname
+  // https://html.spec.whatwg.org/C/#prod-potentialcustomelementname
   static bool IsPotentialCustomElementName8BitChar(LChar ch) {
     return IsASCIILower(ch) || IsASCIIDigit(ch) || ch == '-' || ch == '.' ||
            ch == '_' || ch == 0xb7 || (0xc0 <= ch && ch != 0xd7 && ch != 0xf7);
diff --git a/third_party/blink/renderer/platform/text/character_property_data.h b/third_party/blink/renderer/platform/text/character_property_data.h
index 7d2cf90cb5a08b..0b40eb8a7f3913 100644
--- a/third_party/blink/renderer/platform/text/character_property_data.h
+++ b/third_party/blink/renderer/platform/text/character_property_data.h
@@ -211,7 +211,7 @@ static const UChar32 kIsUprightInMixedVerticalRanges[] = {
     0x100000, 0x10FFFD,
 };
 
-// https://html.spec.whatwg.org/multipage/scripting.html#prod-potentialcustomelementname
+// https://html.spec.whatwg.org/C/#prod-potentialcustomelementname
 static const UChar32 kIsPotentialCustomElementNameCharArray[] = {
     '-', '.', '_', 0xB7,
 };
diff --git a/third_party/blink/renderer/platform/text/text_direction.h b/third_party/blink/renderer/platform/text/text_direction.h
index 3385465093f26b..a3f71b81b58504 100644
--- a/third_party/blink/renderer/platform/text/text_direction.h
+++ b/third_party/blink/renderer/platform/text/text_direction.h
@@ -36,7 +36,7 @@ namespace blink {
 //
 // Used for explicit directions such as in the HTML dir attribute or the CSS
 // 'direction' property.
-// https://html.spec.whatwg.org/multipage/dom.html#the-dir-attribute
+// https://html.spec.whatwg.org/C/#the-dir-attribute
 // https://drafts.csswg.org/css-writing-modes/#direction
 //
 // Also used for resolved directions by UAX#9 UNICODE BIDIRECTIONAL ALGORITHM.
diff --git a/third_party/blink/renderer/platform/weborigin/security_origin.cc b/third_party/blink/renderer/platform/weborigin/security_origin.cc
index 49a244180ac18f..d629c18cab9d46 100644
--- a/third_party/blink/renderer/platform/weborigin/security_origin.cc
+++ b/third_party/blink/renderer/platform/weborigin/security_origin.cc
@@ -320,7 +320,7 @@ bool SecurityOrigin::CanAccess(const SecurityOrigin* other,
   }
 
   // document.domain handling, as per
-  // https://html.spec.whatwg.org/multipage/browsers.html#dom-document-domain:
+  // https://html.spec.whatwg.org/C/#dom-document-domain:
   //
   // 1) Neither document has set document.domain. In this case, we insist
   //    that the scheme, host, and port of the URLs match.
diff --git a/third_party/blink/renderer/platform/weborigin/security_origin.h b/third_party/blink/renderer/platform/weborigin/security_origin.h
index 648e2c49ee9fab..94b20058071e0e 100644
--- a/third_party/blink/renderer/platform/weborigin/security_origin.h
+++ b/third_party/blink/renderer/platform/weborigin/security_origin.h
@@ -55,7 +55,7 @@ struct SecurityOriginHash;
 // tuple, such as the tuple origin (https, chromium.org, null, null). However,
 // there are also opaque origins which do not have a corresponding tuple.
 //
-// See also: https://html.spec.whatwg.org/multipage/origin.html#concept-origin
+// See also: https://html.spec.whatwg.org/C/#concept-origin
 class PLATFORM_EXPORT SecurityOrigin : public RefCounted<SecurityOrigin> {
   WTF_MAKE_NONCOPYABLE(SecurityOrigin);
 
diff --git a/third_party/blink/renderer/platform/wtf/text/string_to_number.h b/third_party/blink/renderer/platform/wtf/text/string_to_number.h
index a80984d577d9c1..ae9fdedebe7cf0 100644
--- a/third_party/blink/renderer/platform/wtf/text/string_to_number.h
+++ b/third_party/blink/renderer/platform/wtf/text/string_to_number.h
@@ -16,7 +16,7 @@ enum class NumberParsingResult {
   kError,
   // For UInt functions, kOverflowMin never happens. Negative numbers are
   // treated as kError. This behavior matches to the HTML standard.
-  // https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#rules-for-parsing-non-negative-integers
+  // https://html.spec.whatwg.org/C/#rules-for-parsing-non-negative-integers
   kOverflowMin,
   kOverflowMax,
 };