diff --git a/packages/driver/cypress/integration/commands/net_stubbing_spec.ts b/packages/driver/cypress/integration/commands/net_stubbing_spec.ts
index ab6ddc5c14c2..ae52808b94fa 100644
--- a/packages/driver/cypress/integration/commands/net_stubbing_spec.ts
+++ b/packages/driver/cypress/integration/commands/net_stubbing_spec.ts
@@ -1679,6 +1679,217 @@ describe('network stubbing', { retries: { runMode: 2, openMode: 0 } }, function
       cy.visit('/fixtures/utf8-post.html')
     })
 
+    // https://github.com/cypress-io/cypress/issues/16327
+    context('request url querystring', () => {
+      // In the code below, cy.window() is used instead of $.get.
+      // It's because XHR is not sent on Firefox and it's flaky on Chrome.
+      it('parse query correctly', () => {
+        cy.intercept({ url: '/users*' }, (req) => {
+          expect(req.query.someKey).to.deep.equal('someValue')
+          expect(req.query).to.deep.equal({ someKey: 'someValue' })
+        }).as('getUrl')
+
+        cy.window().then((win) => {
+          const xhr = new win.XMLHttpRequest()
+
+          xhr.open('GET', '/users?someKey=someValue')
+          xhr.send()
+        })
+
+        cy.wait('@getUrl')
+      })
+
+      context('reconcile changes', () => {
+        it('by assigning a new query parameter obj', () => {
+          cy.intercept({ url: '/users*' }, (req) => {
+            req.query = {
+              a: 'b',
+            }
+
+            expect(req.url).to.eq('http://localhost:3500/users?a=b')
+          }).as('getUrl')
+
+          cy.window().then((win) => {
+            const xhr = new win.XMLHttpRequest()
+
+            xhr.open('GET', '/users?someKey=someValue')
+            xhr.send()
+          })
+
+          cy.wait('@getUrl')
+        })
+
+        it('by setting new properties', () => {
+          cy.intercept({ url: '/users*' }, (req) => {
+            expect(req.query.a).to.eq('b')
+            req.query.c = 'd'
+
+            expect(req.url).to.eq('http://localhost:3500/users?a=b&c=d')
+          }).as('getUrl')
+
+          cy.window().then((win) => {
+            const xhr = new win.XMLHttpRequest()
+
+            xhr.open('GET', '/users?a=b')
+            xhr.send()
+          })
+
+          cy.wait('@getUrl')
+        })
+
+        it('by doing both', () => {
+          cy.intercept({ url: '/users*' }, (req) => {
+            req.query = {
+              a: 'b',
+            }
+
+            expect(req.query.a).to.eq('b')
+            req.query.c = 'd'
+
+            expect(req.url).to.eq('http://localhost:3500/users?a=b&c=d')
+          }).as('getUrl')
+
+          cy.window().then((win) => {
+            const xhr = new win.XMLHttpRequest()
+
+            xhr.open('GET', '/users?someKey=someValue')
+            xhr.send()
+          })
+
+          cy.wait('@getUrl')
+        })
+
+        it('by deleting query member', () => {
+          cy.intercept({ url: '/users*' }, (req) => {
+            req.query = {
+              a: 'b',
+              c: 'd',
+            }
+
+            delete req.query.c
+
+            expect(req.url).to.eq('http://localhost:3500/users?a=b')
+          }).as('getUrl')
+
+          cy.window().then((win) => {
+            const xhr = new win.XMLHttpRequest()
+
+            xhr.open('GET', '/users?someKey=someValue')
+            xhr.send()
+          })
+
+          cy.wait('@getUrl')
+        })
+
+        context('by setting new url', () => {
+          it('absolute path', () => {
+            cy.intercept({ url: '/users*' }, (req) => {
+              req.url = 'http://localhost:3500/users?a=b'
+
+              expect(req.query).to.deep.eq({ a: 'b' })
+            }).as('getUrl')
+
+            cy.window().then((win) => {
+              const xhr = new win.XMLHttpRequest()
+
+              xhr.open('GET', '/users?someKey=someValue')
+              xhr.send()
+            })
+
+            cy.wait('@getUrl')
+          })
+
+          it('relative path', () => {
+            cy.intercept({ url: '/users*' }, (req) => {
+              req.url = '/users?a=b'
+
+              expect(req.query).to.deep.eq({ a: 'b' })
+              expect(req.url).to.eq('http://localhost:3500/users?a=b')
+            }).as('getUrl')
+
+            cy.window().then((win) => {
+              const xhr = new win.XMLHttpRequest()
+
+              xhr.open('GET', '/users?someKey=someValue')
+              xhr.send()
+            })
+
+            cy.wait('@getUrl')
+          })
+
+          it('empty string', () => {
+            cy.intercept({ url: '/users*' }, (req) => {
+              req.url = ''
+
+              expect(req.query).to.deep.eq({})
+            }).as('getUrl')
+
+            cy.window().then((win) => {
+              const xhr = new win.XMLHttpRequest()
+
+              xhr.open('GET', '/users?someKey=someValue')
+              xhr.send()
+            })
+
+            cy.wait('@getUrl')
+          })
+        })
+
+        context('throwing errors correctly', () => {
+          it('defineproperty', (done) => {
+            cy.on('fail', (err) => {
+              expect(err.message).to.eq('`defineProperty()` is not allowed.')
+
+              done()
+            })
+
+            cy.intercept({ url: '/users*' }, (req) => {
+              Object.defineProperty(req.query, 'key', {
+                enumerable: false,
+                configurable: false,
+                writable: false,
+                value: 'static',
+              })
+
+              expect(req.query).to.deep.eq({})
+            }).as('getUrl')
+
+            cy.window().then((win) => {
+              const xhr = new win.XMLHttpRequest()
+
+              xhr.open('GET', '/users?someKey=someValue')
+              xhr.send()
+            })
+
+            cy.wait('@getUrl')
+          })
+
+          it('setPrototypeOf', (done) => {
+            cy.on('fail', (err) => {
+              expect(err.message).to.eq('`setPrototypeOf()` is not allowed.')
+
+              done()
+            })
+
+            cy.intercept({ url: '/users*' }, (req) => {
+              Object.setPrototypeOf(req.query, null)
+
+              expect(req.query).to.deep.eq({})
+            }).as('getUrl')
+
+            cy.window().then((win) => {
+              const xhr = new win.XMLHttpRequest()
+
+              xhr.open('GET', '/users?someKey=someValue')
+              xhr.send()
+            })
+
+            cy.wait('@getUrl')
+          })
+        })
+      })
+    })
+
     context('request events', function () {
       context('can end response', () => {
         for (const eventName of ['before:response', 'response']) {
diff --git a/packages/driver/src/cy/net-stubbing/events/before-request.ts b/packages/driver/src/cy/net-stubbing/events/before-request.ts
index f0911e4bf90b..a2b2f5c61918 100644
--- a/packages/driver/src/cy/net-stubbing/events/before-request.ts
+++ b/packages/driver/src/cy/net-stubbing/events/before-request.ts
@@ -119,8 +119,90 @@ export const onBeforeRequest: HandlerFn<CyHttpMessages.IncomingRequest> = (Cypre
   let resolved = false
   let handlerCompleted = false
 
+  const createQueryObject = () => {
+    try {
+      if (/^(?:[a-z]+:)?\/\//i.test(req.url) === false) {
+        const { protocol, hostname, port } = window.location
+
+        req.url = `${protocol}//${hostname}${port ? `:${port}` : ''}${req.url}`
+      }
+
+      const url = new URL(req.url)
+      const urlSearchParams = new URLSearchParams(url.search)
+      const result = {}
+
+      for (let pair of urlSearchParams.entries()) {
+        result[pair[0]] = pair[1]
+      }
+
+      return result
+    } catch { // avoid when url is "".
+      return {}
+    }
+  }
+
+  const updateUrlParams = (paramsObj) => {
+    const url = new URL(req.url)
+    const urlSearchParams = new URLSearchParams(paramsObj)
+
+    url.search = urlSearchParams.toString()
+    req.url = url.toString()
+  }
+
+  const createQueryProxy = (obj) => {
+    return new Proxy(obj, {
+      set (target, key, value) {
+        target[key] = value
+
+        updateUrlParams(target)
+
+        return true
+      },
+
+      deleteProperty (target, key) {
+        delete target[key]
+
+        updateUrlParams(target)
+
+        return true
+      },
+
+      defineProperty () {
+        $errUtils.throwErrByPath('net_stubbing.request_handling.defineproperty_is_not_allowed')
+
+        return false
+      },
+
+      setPrototypeOf () {
+        $errUtils.throwErrByPath('net_stubbing.request_handling.setprototypeof_is_not_allowed')
+
+        return false
+      },
+    })
+  }
+
+  let queryObj = createQueryObject()
+  let queryProxy = createQueryProxy(queryObj)
+
   const userReq: CyHttpMessages.IncomingHttpRequest = {
     ...req,
+    get query () {
+      return queryProxy
+    },
+    set query (userQuery) {
+      updateUrlParams(userQuery)
+      queryProxy = createQueryProxy(userQuery)
+    },
+    get url () {
+      return req.url
+    },
+    set url (userUrl) {
+      req.url = userUrl
+
+      // reset query variables
+      queryObj = createQueryObject()
+      queryProxy = createQueryProxy(queryObj)
+    },
     on (eventName, handler) {
       if (!validEvents.includes(eventName)) {
         return $errUtils.throwErrByPath('net_stubbing.request_handling.unknown_event', {
diff --git a/packages/driver/src/cypress/error_messages.js b/packages/driver/src/cypress/error_messages.js
index 16814947e632..cd3bba2d3adb 100644
--- a/packages/driver/src/cypress/error_messages.js
+++ b/packages/driver/src/cypress/error_messages.js
@@ -1001,6 +1001,8 @@ module.exports = {
           You passed: ${format(eventName)}`, 10)
       },
       event_needs_handler: `\`req.on()\` requires the second parameter to be a function.`,
+      defineproperty_is_not_allowed: `\`defineProperty()\` is not allowed.`,
+      setprototypeof_is_not_allowed: `\`setPrototypeOf()\` is not allowed.`,
     },
     request_error: {
       network_error: ({ innerErr, req, route }) => {
diff --git a/packages/net-stubbing/lib/external-types.ts b/packages/net-stubbing/lib/external-types.ts
index d5df49498e75..cbd2222b29ca 100644
--- a/packages/net-stubbing/lib/external-types.ts
+++ b/packages/net-stubbing/lib/external-types.ts
@@ -131,6 +131,10 @@ export namespace CyHttpMessages {
      * Request URL.
      */
     url: string
+    /**
+     * URL query string as object.
+     */
+    query: Record<string, string|number>
     /**
      * The HTTP version used in the request. Read only.
      */