diff --git a/.github/workflows/integration.yml b/.github/workflows/integration.yml
index 1249f20532f..f6f81828e17 100644
--- a/.github/workflows/integration.yml
+++ b/.github/workflows/integration.yml
@@ -3,10 +3,10 @@ name: Integration Tests
 on:
   push:
     branches:
-      - master
+      - main
   pull_request:
     branches:
-      - master
+      - main
 
 jobs:
   job:
diff --git a/CHANGELOG-0.x.md b/CHANGELOG-0.x.md
index ea3fa82446a..5463a61a4e9 100644
--- a/CHANGELOG-0.x.md
+++ b/CHANGELOG-0.x.md
@@ -363,21 +363,21 @@ Thanks to [@Timer](https://github.com/timer) for cutting this release.
 
   - [#1489](https://github.com/facebook/create-react-app/pull/1489) Support setting `"homepage"` to `"."` to generate relative asset paths. ([@tibdex](https://github.com/tibdex))
 
-    Applications that don’t use the HTML5 `pushState` API can now be built to be served from any relative URL. To enable this, specify `"."` as your `homepage` setting in `package.json`. It used to be possible before with a few known bugs, but they should be fixed now. See [Serving the Same Build from Different Paths](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#serving-the-same-build-from-different-paths).
+    Applications that don’t use the HTML5 `pushState` API can now be built to be served from any relative URL. To enable this, specify `"."` as your `homepage` setting in `package.json`. It used to be possible before with a few known bugs, but they should be fixed now. See [Serving the Same Build from Different Paths](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#serving-the-same-build-from-different-paths).
 
   - [#937](https://github.com/facebook/create-react-app/pull/1504) Add `PUBLIC_URL` environment variable for advanced use. ([@EnoahNetzach](https://github.com/EnoahNetzach))
 
-    If you use a CDN to serve the app, you can now specify `PUBLIC_URL` environment variable to override the base URL (including the hostname) for resources referenced from the built code. This new variable is mentioned in the new [Advanced Configuration](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#advanced-configuration) section.
+    If you use a CDN to serve the app, you can now specify `PUBLIC_URL` environment variable to override the base URL (including the hostname) for resources referenced from the built code. This new variable is mentioned in the new [Advanced Configuration](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#advanced-configuration) section.
 
   - [#1440](https://github.com/facebook/create-react-app/pull/1440) Make all `REACT_APP_*` environment variables accessible in `index.html`. ([@jihchi](https://github.com/jihchi))
 
-    This makes all environment variables previously available in JS, also available in the HTML file, for example `%REACT_APP_MY_VARIABLE%`. See [Referencing Environment Variables in HTML](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#referencing-environment-variables-in-the-html).
+    This makes all environment variables previously available in JS, also available in the HTML file, for example `%REACT_APP_MY_VARIABLE%`. See [Referencing Environment Variables in HTML](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#referencing-environment-variables-in-the-html).
 
 - `react-dev-utils`
 
   - [#1148](https://github.com/facebook/create-react-app/pull/1148) Configure which browser to open with `npm start`. ([@GAumala](https://github.com/GAumala))
 
-    You can now disable the automatic browser launching by setting the `BROWSER` environment variable to `none`. You can also specify a different browser (or an arbitrary script) to open by default, [as supported by `opn` command](https://github.com/sindresorhus/opn#app) that we use under the hood. See [Advanced Configuration](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#advanced-configuration).
+    You can now disable the automatic browser launching by setting the `BROWSER` environment variable to `none`. You can also specify a different browser (or an arbitrary script) to open by default, [as supported by `opn` command](https://github.com/sindresorhus/opn#app) that we use under the hood. See [Advanced Configuration](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#advanced-configuration).
 
 #### :boom: Breaking Change
 
@@ -393,7 +393,7 @@ Thanks to [@Timer](https://github.com/timer) for cutting this release.
 
   - [#1264](https://github.com/facebook/create-react-app/pull/1264) Remove interactive shell check when opening browser on start. ([@CaryLandholt](https://github.com/CaryLandholt))
 
-    Non-interactive terminals no longer automatically disable launching of the browser. Instead, you need to [specify `none` as `BROWSER` environment variable](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#advanced-configuration) if you wish to disable it.
+    Non-interactive terminals no longer automatically disable launching of the browser. Instead, you need to [specify `none` as `BROWSER` environment variable](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#advanced-configuration) if you wish to disable it.
 
 #### :bug: Bug Fix
 
@@ -823,7 +823,7 @@ Thanks to [@fson](https://github.com/fson) for cutting this release.
 
   - [#944](https://github.com/facebook/create-react-app/pull/944) Crash the build during CI whenever linter warnings are encountered. ([@excitement-engineer](https://github.com/excitement-engineer))
 
-    Linter warnings and errors are now checked during a continuous integration build (set by the `CI` environment variable) and the build will fail if any issues are found. See [Continuous Integration](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#continuous-integration) for more information.
+    Linter warnings and errors are now checked during a continuous integration build (set by the `CI` environment variable) and the build will fail if any issues are found. See [Continuous Integration](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#continuous-integration) for more information.
 
   - [#1090](https://github.com/facebook/create-react-app/pull/1090) Enable proxying of WebSockets. ([@dceddia](https://github.com/dceddia))
 
@@ -1109,8 +1109,8 @@ npm install --save-dev --save-exact react-scripts@0.5.1
 
 ### Build Dependency (`react-scripts`)
 
-- Adds [support for `public` folder](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#using-the-public-folder) with arbitrary assets. ([@gaearon](https://github.com/gaearon) in [#703](https://github.com/facebook/create-react-app/pull/703))
-- You can now [specify defaults](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#adding-development-environment-variables-in-env) for environment variables with `.env` file. ([@ayrton](https://github.com/ayrton) in [#695](https://github.com/facebook/create-react-app/pull/695))
+- Adds [support for `public` folder](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#using-the-public-folder) with arbitrary assets. ([@gaearon](https://github.com/gaearon) in [#703](https://github.com/facebook/create-react-app/pull/703))
+- You can now [specify defaults](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#adding-development-environment-variables-in-env) for environment variables with `.env` file. ([@ayrton](https://github.com/ayrton) in [#695](https://github.com/facebook/create-react-app/pull/695))
 - Ejecting now generates proper `.babelrc` and `.eslintrc`. ([@fson](https://github.com/fson) in [#689](https://github.com/facebook/create-react-app/pull/689), [@gaearon](https://github.com/gaearon) in [#705](https://github.com/facebook/create-react-app/pull/705))
 - Some React warnings now [include the component stacktrace](https://twitter.com/dan_abramov/status/779308833399332864). ([@gaearon](https://github.com/gaearon) in [#716](https://github.com/facebook/create-react-app/pull/716))
 - `npm start` doesn’t fail in a composed Docker container. ([@arekkas](https://github.com/arekkas) in [#711](https://github.com/facebook/create-react-app/issues/711))
@@ -1166,7 +1166,7 @@ You would need to move both `index.html` and `src/favicon.ico` into the `public`
 <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico" />
 ```
 
-This ensures it become a part of the build output, and resolves correctly both with client-side routing and non-root `homepage` in `package.json`. Read more about [using the `public` folder](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#using-the-public-folder) and [why these changes were made](https://github.com/facebook/create-react-app/pull/703).
+This ensures it become a part of the build output, and resolves correctly both with client-side routing and non-root `homepage` in `package.json`. Read more about [using the `public` folder](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#using-the-public-folder) and [why these changes were made](https://github.com/facebook/create-react-app/pull/703).
 
 ## 0.4.3 (September 18, 2016)
 
@@ -1260,9 +1260,9 @@ npm install --save-dev --save-exact react-scripts@0.4.0
 
 Paths like `/src/somefile.png` used to be served in development, but only by accident. They never worked in production builds. Since 0.4.0, we [don’t serve static files by default in development anymore either](https://github.com/facebook/create-react-app/pull/551). This removes a dangerous inconsistency that we never intentionally supported.
 
-If you need a static file to be part for the build, [import it from JavaScript and you will get its filename](https://github.com/facebook/create-react-app/blob/master/template/README.md#adding-images-and-fonts). This ensures it gets included into the production build as well, and its filename contains the content hash.
+If you need a static file to be part for the build, [import it from JavaScript and you will get its filename](https://github.com/facebook/create-react-app/blob/main/template/README.md#adding-images-and-fonts). This ensures it gets included into the production build as well, and its filename contains the content hash.
 
-If you used static files with `<link href>`, [read this new guide](https://github.com/facebook/create-react-app/blob/master/template/README.md#referring-to-static-assets-from-link-href) on how to make sure these files get included into the builds. For example, you can replace `<link href="/src/favicons/favicon-32.png">` with `<link href="./src/favicons/favicon-32.png">`, and then webpack will recognize it and include it into the build.
+If you used static files with `<link href>`, [read this new guide](https://github.com/facebook/create-react-app/blob/main/template/README.md#referring-to-static-assets-from-link-href) on how to make sure these files get included into the builds. For example, you can replace `<link href="/src/favicons/favicon-32.png">` with `<link href="./src/favicons/favicon-32.png">`, and then webpack will recognize it and include it into the build.
 
 If you referenced some other files from `index.html`, please file an issue to discuss your use case. In the meantime, you can serve them from a separate static server until your use case is supported.
 
@@ -1284,7 +1284,7 @@ npm install --save-dev --save-exact react-scripts@0.3.1
 
 ### Build Dependency (`react-scripts`)
 
-- Testing is [now supported](https://github.com/facebook/create-react-app/blob/master/template/README.md#running-tests)! ([Jest project contributors](https://github.com/facebook/jest/pulls?q=is%3Apr+is%3Aclosed), [@cpojer](https://github.com/cpojer) in [#250](https://github.com/facebook/create-react-app/pull/250), [@gaearon](https://github.com/gaearon) in [#378](https://github.com/facebook/create-react-app/pull/378), [#530](https://github.com/facebook/create-react-app/pull/530), [#533](https://github.com/facebook/create-react-app/pull/533))
+- Testing is [now supported](https://github.com/facebook/create-react-app/blob/main/template/README.md#running-tests)! ([Jest project contributors](https://github.com/facebook/jest/pulls?q=is%3Apr+is%3Aclosed), [@cpojer](https://github.com/cpojer) in [#250](https://github.com/facebook/create-react-app/pull/250), [@gaearon](https://github.com/gaearon) in [#378](https://github.com/facebook/create-react-app/pull/378), [#530](https://github.com/facebook/create-react-app/pull/530), [#533](https://github.com/facebook/create-react-app/pull/533))
 - Static files such as CSS, images, and fonts, can now exist outside `src` directory. ([@fson](https://github.com/fson) in [#504](https://github.com/facebook/create-react-app/pull/504))
 - **Breaking Change:** Local paths in `<link href>` in `index.html` will now be correctly resolved, so deleting `favicon.ico` is not an error anymore. ([@andreypopp](https://github.com/andreypopp) in [#428](https://github.com/facebook/create-react-app/pull/428))
 - Removed an annoying lint rule that warned for `<div ref={node => this.node = node}>`. ([@mrscobbler](https://github.com/mrscobbler) in [#529](https://github.com/facebook/create-react-app/pull/529))
@@ -1331,7 +1331,7 @@ Since 0.3.0 added a test runner, we recommend that you add it to the `scripts` s
   }
 ```
 
-[Then read the testing guide to learn more about using it!](https://github.com/facebook/create-react-app/blob/master/template/README.md#running-tests)
+[Then read the testing guide to learn more about using it!](https://github.com/facebook/create-react-app/blob/main/template/README.md#running-tests)
 
 ## 0.2.3 (August 25, 2016)
 
@@ -1406,7 +1406,7 @@ Newly created projects will use `0.2.1` automatically. You **don’t** need to u
 - A `.babelrc` in parent directory no longer causes an error ([@alexzherdev](https://github.com/alexzherdev) in [#236](https://github.com/facebook/create-react-app/pull/236))
 - Files with `.json` extension are now discovered ([@gaearon](https://github.com/gaearon) in [a11d6a](https://github.com/facebook/create-react-app/commit/a11d6a398f487f9163880dd34667b1d3e14b147a))
 - Bug fixes from transitive dependencies are included ([#126](https://github.com/facebook/create-react-app/issues/126))
-- Linting now works with IDEs if you follow [these](https://github.com/facebook/create-react-app/blob/master/template/README.md#display-lint-output-in-the-editor) instructions ([@keyanzhang](https://github.com/keyanzhang) in [#149](https://github.com/facebook/create-react-app/pull/149))
+- Linting now works with IDEs if you follow [these](https://github.com/facebook/create-react-app/blob/main/template/README.md#display-lint-output-in-the-editor) instructions ([@keyanzhang](https://github.com/keyanzhang) in [#149](https://github.com/facebook/create-react-app/pull/149))
 - After building, we now print gzipped bundle size ([@lvwrence](https://github.com/lvwrence) in [#229](https://github.com/facebook/create-react-app/pull/229))
 
 ### Global CLI (`create-react-app`)
@@ -1428,7 +1428,7 @@ Inside any created project that has not been ejected, run:
 npm install --save-dev --save-exact react-scripts@0.2.0
 ```
 
-You may need to fix a few lint warnings about missing `<img alt>` tag, but everything else should work out of the box. If you intend to deploy your site to GitHub Pages, you may now [add `homepage` field to `package.json`](https://github.com/facebook/create-react-app/blob/master/template/README.md#deploy-to-github-pages). If you had [issues with integrating editor linter plugins](https://github.com/facebook/create-react-app/issues/124), follow [these new instructions](https://github.com/facebook/create-react-app/blob/master/template/README.md#display-lint-output-in-the-editor).
+You may need to fix a few lint warnings about missing `<img alt>` tag, but everything else should work out of the box. If you intend to deploy your site to GitHub Pages, you may now [add `homepage` field to `package.json`](https://github.com/facebook/create-react-app/blob/main/template/README.md#deploy-to-github-pages). If you had [issues with integrating editor linter plugins](https://github.com/facebook/create-react-app/issues/124), follow [these new instructions](https://github.com/facebook/create-react-app/blob/main/template/README.md#display-lint-output-in-the-editor).
 
 ## 0.1.0 (July 22, 2016)
 
diff --git a/CHANGELOG-1.x.md b/CHANGELOG-1.x.md
index cc629cf5f95..f797a8e54a3 100644
--- a/CHANGELOG-1.x.md
+++ b/CHANGELOG-1.x.md
@@ -1365,7 +1365,7 @@ or
 yarn add --dev --exact react-scripts@1.0.2
 ```
 
-If you previously had issues with an `Invalid Host Header` error, [follow these new instructions](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#invalid-host-header-errors-after-configuring-proxy) to fix it.
+If you previously had issues with an `Invalid Host Header` error, [follow these new instructions](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#invalid-host-header-errors-after-configuring-proxy) to fix it.
 
 ## 1.0.1 (May 19, 2017)
 
@@ -1572,7 +1572,7 @@ If you still have the problem please file an issue.
 
 Unhandled Promise rejections will now crash tests. You can fix them by explicitly catching the errors you don’t care about.
 
-#### How to turn my app into a [Progressive Web App](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#making-a-progressive-web-app)?
+#### How to turn my app into a [Progressive Web App](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/template/README.md#making-a-progressive-web-app)?
 
 After the regular update procedure above, add these line to `<head>` in `public/index.html`:
 
@@ -1588,9 +1588,7 @@ After the regular update procedure above, add these line to `<head>` in `public/
 Add `<noscript>` to `<body>` in `public/index.html`:
 
 ```html
-<noscript>
-  You need to enable JavaScript to run this app.
-</noscript>
+<noscript> You need to enable JavaScript to run this app. </noscript>
 ```
 
 Then create a file called `public/manifest.json` that looks like this:
diff --git a/CHANGELOG-2.x.md b/CHANGELOG-2.x.md
index 5080171a165..ecc3d7e8592 100644
--- a/CHANGELOG-2.x.md
+++ b/CHANGELOG-2.x.md
@@ -823,7 +823,7 @@ import 'react-app-polyfill/ie9'; // For IE 9-11 support
 import 'react-app-polyfill/ie11'; // For IE 11 support
 ```
 
-You can read more about [these polyfills here](https://github.com/facebook/create-react-app/tree/master/packages/react-app-polyfill).
+You can read more about [these polyfills here](https://github.com/facebook/create-react-app/tree/main/packages/react-app-polyfill).
 
 ### Dynamic `import()` of a CommonJS module now has a `.default` property
 
@@ -845,7 +845,7 @@ We previously allowed code splitting with a webpack-specific directive, `require
 **Single Module**
 
 ```js
-require.ensure(['module-a'], function() {
+require.ensure(['module-a'], function () {
   var a = require('module-a');
   // ...
 });
@@ -859,7 +859,7 @@ import('module-a').then(a => {
 **Multiple Module**
 
 ```js
-require.ensure(['module-a', 'module-b'], function() {
+require.ensure(['module-a', 'module-b'], function () {
   var a = require('module-a');
   var b = require('module-b');
   // ...
@@ -913,7 +913,7 @@ Next, create `src/setupProxy.js` and place the following contents in it:
 ```js
 const proxy = require('http-proxy-middleware');
 
-module.exports = function(app) {
+module.exports = function (app) {
   // ...
 };
 ```
@@ -936,7 +936,7 @@ Place entries into `src/setupProxy.js` like so:
 ```js
 const proxy = require('http-proxy-middleware');
 
-module.exports = function(app) {
+module.exports = function (app) {
   app.use(proxy('/api', { target: 'http://localhost:5000/' }));
   app.use(proxy('/*.svg', { target: 'http://localhost:5000/' }));
 };
diff --git a/CHANGELOG-3.x.md b/CHANGELOG-3.x.md
index f73718f970c..53a1e638d23 100644
--- a/CHANGELOG-3.x.md
+++ b/CHANGELOG-3.x.md
@@ -330,7 +330,7 @@ v3.3.0 is a minor release that adds new features, including custom templates and
 
 You can now create a new app using custom templates.
 
-We've published our existing templates as [`cra-template`](https://github.com/facebook/create-react-app/tree/master/packages/cra-template) and [`cra-template-typescript`](https://github.com/facebook/create-react-app/tree/master/packages/cra-template-typescript), but we expect to see many great templates from the community over the coming weeks.
+We've published our existing templates as [`cra-template`](https://github.com/facebook/create-react-app/tree/main/packages/cra-template) and [`cra-template-typescript`](https://github.com/facebook/create-react-app/tree/main/packages/cra-template-typescript), but we expect to see many great templates from the community over the coming weeks.
 
 The below command shows how you can create a new app with `cra-template-typescript`.
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index bb515bb504f..716c0e79925 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -48,7 +48,7 @@ Please also provide a **test plan**, i.e. specify how you verified that your add
 ## Folder Structure of Create React App
 
 `create-react-app` is a monorepo, meaning it is divided into independent sub-packages.<br>
-These packages can be found in the [`packages/`](https://github.com/facebook/create-react-app/tree/master/packages) directory.
+These packages can be found in the [`packages/`](https://github.com/facebook/create-react-app/tree/main/packages) directory.
 
 ### Overview of directory structure
 
@@ -63,27 +63,27 @@ packages/
 
 ### Package Descriptions
 
-#### [babel-preset-react-app](https://github.com/facebook/create-react-app/tree/master/packages/babel-preset-react-app)
+#### [babel-preset-react-app](https://github.com/facebook/create-react-app/tree/main/packages/babel-preset-react-app)
 
 This package is a babel preset intended to be used with `react-scripts`.<br>
 It targets platforms that React is designed to support (IE 11+) and enables experimental features used heavily at Facebook.<br>
 This package is enabled by default for all `create-react-app` scaffolded applications.
 
-#### [create-react-app](https://github.com/facebook/create-react-app/tree/master/packages/create-react-app)
+#### [create-react-app](https://github.com/facebook/create-react-app/tree/main/packages/create-react-app)
 
 The global CLI command code can be found in this directory, and shouldn't often be changed. It should run on Node 0.10+.
 
-#### [eslint-config-react-app](https://github.com/facebook/create-react-app/tree/master/packages/eslint-config-react-app)
+#### [eslint-config-react-app](https://github.com/facebook/create-react-app/tree/main/packages/eslint-config-react-app)
 
 This package contains a conservative set of rules focused on making errors apparent and enforces no style rules.<br>
 This package is enabled by default for all `create-react-app` scaffolded applications.
 
-#### [react-dev-utils](https://github.com/facebook/create-react-app/tree/master/packages/react-dev-utils)
+#### [react-dev-utils](https://github.com/facebook/create-react-app/tree/main/packages/react-dev-utils)
 
 This package contains utilities used for `react-scripts` and sibling packages.<br>
 Its main purpose is to conceal code which the user shouldn't be burdened with upon ejecting.
 
-#### [react-scripts](https://github.com/facebook/create-react-app/tree/master/packages/react-scripts)
+#### [react-scripts](https://github.com/facebook/create-react-app/tree/main/packages/react-scripts)
 
 This package is the heart of the project, which contains the scripts for setting up the development server, building production builds, configuring all software used, etc.<br>
 All functionality must be retained (and configuration given to the user) if they choose to eject.
@@ -163,7 +163,7 @@ Make sure to test the released version! If you want to be extra careful, you can
 1. Go to the `docusaurus/website` directory
 2. Run `yarn build`
 3. You'll need an [access token for the GitHub API](https://help.github.com/articles/creating-an-access-token-for-command-line-use/). Save it to this environment variable: `export GITHUB_AUTH="..."`
-4. Run `GIT_USER=<GITHUB_USERNAME> CURRENT_BRANCH=master USE_SSH=true yarn deploy`
+4. Run `GIT_USER=<GITHUB_USERNAME> CURRENT_BRANCH=main USE_SSH=true yarn deploy`
 
 ---
 
diff --git a/README.md b/README.md
index f688165eb0f..1d80321d484 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# Create React App [![Build Status](https://dev.azure.com/facebook/create-react-app/_apis/build/status/facebook.create-react-app?branchName=master)](https://dev.azure.com/facebook/create-react-app/_build/latest?definitionId=1&branchName=master) [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-green.svg)](https://github.com/facebook/create-react-app/blob/master/CONTRIBUTING.md)
+# Create React App [![Build Status](https://dev.azure.com/facebook/create-react-app/_apis/build/status/facebook.create-react-app?branchName=main)](https://dev.azure.com/facebook/create-react-app/_build/latest?definitionId=1&branchName=main) [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-green.svg)](https://github.com/facebook/create-react-app/blob/main/CONTRIBUTING.md)
 
 <img alt="Logo" align="right" src="https://create-react-app.dev/img/logo.svg" width="20%" />
 
@@ -217,4 +217,4 @@ We are grateful to the authors of existing related projects for their ideas and
 
 ## License
 
-Create React App is open source software [licensed as MIT](https://github.com/facebook/create-react-app/blob/master/LICENSE). The Create React App logo is licensed under a [Creative Commons Attribution 4.0 International license](https://creativecommons.org/licenses/by/4.0/).
+Create React App is open source software [licensed as MIT](https://github.com/facebook/create-react-app/blob/main/LICENSE). The Create React App logo is licensed under a [Creative Commons Attribution 4.0 International license](https://creativecommons.org/licenses/by/4.0/).
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 3c89363208b..bce15c646ad 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -3,7 +3,7 @@
 #
 
 trigger:
-  - master
+  - main
 
 variables:
   CI: true
diff --git a/docusaurus/docs/adding-a-sass-stylesheet.md b/docusaurus/docs/adding-a-sass-stylesheet.md
index fb1a23af00b..5a287294155 100644
--- a/docusaurus/docs/adding-a-sass-stylesheet.md
+++ b/docusaurus/docs/adding-a-sass-stylesheet.md
@@ -34,7 +34,7 @@ This will allow you to do imports like
 
 `sass` also supports the `SASS_PATH` variable.
 
-To use imports relative to a path you specify, you can add a [`.env` file](https://github.com/facebook/create-react-app/blob/master/docusaurus/docs/adding-custom-environment-variables.md#adding-development-environment-variables-in-env) at the project root with the path specified in the `SASS_PATH` environment variable. To specify more directories you can add them to `SASS_PATH` separated by a `:` like `path1:path2:path3`.
+To use imports relative to a path you specify, you can add a [`.env` file](https://github.com/facebook/create-react-app/blob/main/docusaurus/docs/adding-custom-environment-variables.md#adding-development-environment-variables-in-env) at the project root with the path specified in the `SASS_PATH` environment variable. To specify more directories you can add them to `SASS_PATH` separated by a `:` like `path1:path2:path3`.
 
 > **Note:** For the Windows operating system, separate your paths by semicolons.
 >
@@ -65,4 +65,4 @@ To use imports relative to a path you specify, you can add a [`.env` file](https
 > # or
 > $ yarn remove node-sass
 > $ yarn add sass
-> ```
\ No newline at end of file
+> ```
diff --git a/docusaurus/docs/custom-templates.md b/docusaurus/docs/custom-templates.md
index 9ae4ae69741..f1caf7568d7 100644
--- a/docusaurus/docs/custom-templates.md
+++ b/docusaurus/docs/custom-templates.md
@@ -19,14 +19,14 @@ npx create-react-app my-app --template [template-name]
 
 We ship two templates by default:
 
-- [`cra-template`](https://github.com/facebook/create-react-app/tree/master/packages/cra-template)
-- [`cra-template-typescript`](https://github.com/facebook/create-react-app/tree/master/packages/cra-template-typescript)
+- [`cra-template`](https://github.com/facebook/create-react-app/tree/main/packages/cra-template)
+- [`cra-template-typescript`](https://github.com/facebook/create-react-app/tree/main/packages/cra-template-typescript)
 
 However, you can find many great community templates by searching for ["cra-template-\*"](https://www.npmjs.com/search?q=cra-template-*) on npm.
 
 ## Building a template
 
-If you're interested in building a custom template, first take a look at how we've built [`cra-template`](https://github.com/facebook/create-react-app/tree/master/packages/cra-template).
+If you're interested in building a custom template, first take a look at how we've built [`cra-template`](https://github.com/facebook/create-react-app/tree/main/packages/cra-template).
 
 A template must have the following structure:
 
diff --git a/docusaurus/docs/documentation-intro.md b/docusaurus/docs/documentation-intro.md
index 8976946c784..aee991f0f40 100644
--- a/docusaurus/docs/documentation-intro.md
+++ b/docusaurus/docs/documentation-intro.md
@@ -18,7 +18,7 @@ This website is only about Create React App.
 
 ## Something Missing?
 
-If you have ideas for more “How To” recipes that should be on this page, [let us know](https://github.com/facebook/create-react-app/issues) or [contribute some!](https://github.com/facebook/create-react-app/tree/master/docusaurus/docs)
+If you have ideas for more “How To” recipes that should be on this page, [let us know](https://github.com/facebook/create-react-app/issues) or [contribute some!](https://github.com/facebook/create-react-app/tree/main/docusaurus/docs)
 
 ## Feedback
 
diff --git a/docusaurus/docs/fetching-data-with-ajax-requests.md b/docusaurus/docs/fetching-data-with-ajax-requests.md
index 22f37e09a06..43bcc902f67 100644
--- a/docusaurus/docs/fetching-data-with-ajax-requests.md
+++ b/docusaurus/docs/fetching-data-with-ajax-requests.md
@@ -11,6 +11,6 @@ The global `fetch` function allows you to make AJAX requests. It takes in a URL
 A Promise represents the eventual result of an asynchronous operation, you can find more information about Promises [here](https://www.promisejs.org/) and [here](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise). Both axios and `fetch()` use Promises under the hood. You can also use the [`async / await`](https://davidwalsh.name/async-await) syntax to reduce the callback nesting.
 
 Make sure the [`fetch()` API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) and [Promises](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise) are available in your target audience's browsers.
-For example, support in Internet Explorer requires a [polyfill](https://github.com/facebook/create-react-app/blob/master/packages/react-app-polyfill/README.md).
+For example, support in Internet Explorer requires a [polyfill](https://github.com/facebook/create-react-app/blob/main/packages/react-app-polyfill/README.md).
 
 You can learn more about making AJAX requests from React components in [the FAQ entry on the React website](https://reactjs.org/docs/faq-ajax.html).
diff --git a/docusaurus/docs/running-tests.md b/docusaurus/docs/running-tests.md
index 4090a1fcd6f..bc45a272acc 100644
--- a/docusaurus/docs/running-tests.md
+++ b/docusaurus/docs/running-tests.md
@@ -5,7 +5,7 @@ title: Running Tests
 
 > Note: this feature is available with `react-scripts@0.3.0` and higher.
 
-> [Read the migration guide to learn how to enable it in older projects!](https://github.com/facebook/create-react-app/blob/master/CHANGELOG-0.x.md#migrating-from-023-to-030)
+> [Read the migration guide to learn how to enable it in older projects!](https://github.com/facebook/create-react-app/blob/main/CHANGELOG-0.x.md#migrating-from-023-to-030)
 
 Create React App uses [Jest](https://jestjs.io/) as its test runner. To prepare for this integration, we did a [major revamp](https://jestjs.io/blog/2016/09/01/jest-15.html) of Jest so if you heard bad things about it years ago, give it another try.
 
@@ -184,7 +184,7 @@ Note that tests run much slower with coverage so it is recommended to run it sep
 
 ### Configuration
 
-The [default configuration](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/scripts/utils/createJestConfig.js) that Create React App uses for Jest can be overridden by adding any of the following supported keys to a Jest config in your package.json.
+The [default configuration](https://github.com/facebook/create-react-app/blob/main/packages/react-scripts/scripts/utils/createJestConfig.js) that Create React App uses for Jest can be overridden by adding any of the following supported keys to a Jest config in your package.json.
 
 Supported overrides:
 
diff --git a/docusaurus/docs/supported-browsers-features.md b/docusaurus/docs/supported-browsers-features.md
index 6a7123de5be..d104c19a0c5 100644
--- a/docusaurus/docs/supported-browsers-features.md
+++ b/docusaurus/docs/supported-browsers-features.md
@@ -6,7 +6,7 @@ sidebar_label: Supported Browsers and Features
 
 ## Supported Browsers
 
-By default, the generated project supports all modern browsers. Support for Internet Explorer 9, 10, and 11 requires polyfills. For a set of polyfills to support older browsers, use [react-app-polyfill](https://github.com/facebook/create-react-app/blob/master/packages/react-app-polyfill/README.md).
+By default, the generated project supports all modern browsers. Support for Internet Explorer 9, 10, and 11 requires polyfills. For a set of polyfills to support older browsers, use [react-app-polyfill](https://github.com/facebook/create-react-app/blob/main/packages/react-app-polyfill/README.md).
 
 ## Supported Language Features
 
@@ -23,9 +23,9 @@ Learn more about [different proposal stages](https://tc39.github.io/process-docu
 
 While we recommend using experimental proposals with some caution, Facebook heavily uses these features in the product code, so we intend to provide [codemods](https://medium.com/@cpojer/effective-javascript-codemods-5a6686bb46fb) if any of these proposals change in the future.
 
-Note that **this project includes no [polyfills](https://github.com/facebook/create-react-app/blob/master/packages/react-app-polyfill/README.md)** by default.
+Note that **this project includes no [polyfills](https://github.com/facebook/create-react-app/blob/main/packages/react-app-polyfill/README.md)** by default.
 
-If you use any other ES6+ features that need **runtime support** (such as `Array.from()` or `Symbol`), make sure you are [including the appropriate polyfills manually](https://github.com/facebook/create-react-app/blob/master/packages/react-app-polyfill/README.md), or that the browsers you are targeting already support them.
+If you use any other ES6+ features that need **runtime support** (such as `Array.from()` or `Symbol`), make sure you are [including the appropriate polyfills manually](https://github.com/facebook/create-react-app/blob/main/packages/react-app-polyfill/README.md), or that the browsers you are targeting already support them.
 
 ## Configuring Supported Browsers
 
diff --git a/docusaurus/docs/updating-to-new-releases.md b/docusaurus/docs/updating-to-new-releases.md
index f8a2fa21850..02e47eb9238 100644
--- a/docusaurus/docs/updating-to-new-releases.md
+++ b/docusaurus/docs/updating-to-new-releases.md
@@ -8,13 +8,14 @@ Create React App is divided into two packages:
 - `create-react-app` is a global command-line utility that you use to create new projects.
 - `react-scripts` is a development dependency in the generated projects (including this one).
 
-When you run `npx create-react-app my-app` it automatically installs the latest version of Create React App.  
-> If you've previously installed `create-react-app` globally via `npm install -g create-react-app`, please visit [Getting Started](getting-started.md) to learn about current installation steps. 
+When you run `npx create-react-app my-app` it automatically installs the latest version of Create React App.
+
+> If you've previously installed `create-react-app` globally via `npm install -g create-react-app`, please visit [Getting Started](getting-started.md) to learn about current installation steps.
 
 Create React App creates the project with the latest version of `react-scripts` so you’ll get all the new features and improvements in newly created apps automatically.
 
-To update an existing project to a new version of `react-scripts`, [open the changelog](https://github.com/facebook/create-react-app/blob/master/CHANGELOG.md), find the version you’re currently on (check `package.json` in this folder if you’re not sure), and apply the migration instructions for the newer versions.
+To update an existing project to a new version of `react-scripts`, [open the changelog](https://github.com/facebook/create-react-app/blob/main/CHANGELOG.md), find the version you’re currently on (check `package.json` in this folder if you’re not sure), and apply the migration instructions for the newer versions.
 
-In most cases bumping the `react-scripts` version in `package.json` and running `npm install` (or `yarn install`) in this folder should be enough, but it’s good to consult the [changelog](https://github.com/facebook/create-react-app/blob/master/CHANGELOG.md) for potential breaking changes.
+In most cases bumping the `react-scripts` version in `package.json` and running `npm install` (or `yarn install`) in this folder should be enough, but it’s good to consult the [changelog](https://github.com/facebook/create-react-app/blob/main/CHANGELOG.md) for potential breaking changes.
 
 We commit to keeping the breaking changes minimal so you can upgrade `react-scripts` painlessly.
diff --git a/docusaurus/website/docusaurus.config.js b/docusaurus/website/docusaurus.config.js
index 6064a3a23dd..571a4643671 100644
--- a/docusaurus/website/docusaurus.config.js
+++ b/docusaurus/website/docusaurus.config.js
@@ -21,7 +21,7 @@ const siteConfig = {
           path: '../docs',
           sidebarPath: require.resolve('./sidebars.json'),
           editUrl:
-            'https://github.com/facebook/create-react-app/edit/master/docusaurus/website',
+            'https://github.com/facebook/create-react-app/edit/main/docusaurus/website',
           showLastUpdateAuthor: true,
           showLastUpdateTime: true,
         },
diff --git a/packages/eslint-config-react-app/index.js b/packages/eslint-config-react-app/index.js
index 06e9fb6287d..603a68b0201 100644
--- a/packages/eslint-config-react-app/index.js
+++ b/packages/eslint-config-react-app/index.js
@@ -280,7 +280,7 @@ module.exports = {
     'jsx-a11y/role-supports-aria-props': 'warn',
     'jsx-a11y/scope': 'warn',
 
-    // https://github.com/facebook/react/tree/master/packages/eslint-plugin-react-hooks
+    // https://github.com/facebook/react/tree/main/packages/eslint-plugin-react-hooks
     'react-hooks/rules-of-hooks': 'error',
 
     // https://github.com/gajus/eslint-plugin-flowtype
diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index c0f66cb1bd4..b0f9d3763aa 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -665,7 +665,7 @@ module.exports = function (webpackEnv) {
       // This is necessary to emit hot updates (CSS and Fast Refresh):
       isEnvDevelopment && new webpack.HotModuleReplacementPlugin(),
       // Experimental hot reloading for React .
-      // https://github.com/facebook/react/tree/master/packages/react-refresh
+      // https://github.com/facebook/react/tree/main/packages/react-refresh
       isEnvDevelopment &&
         shouldUseReactRefresh &&
         new ReactRefreshWebpackPlugin({
diff --git a/packages/react-scripts/template-typescript/README.md b/packages/react-scripts/template-typescript/README.md
index c2021dd7335..3ff8c806ca8 100644
--- a/packages/react-scripts/template-typescript/README.md
+++ b/packages/react-scripts/template-typescript/README.md
@@ -1 +1 @@
-This file has moved [here](https://github.com/facebook/create-react-app/blob/master/packages/cra-template-typescript/template/README.md)
+This file has moved [here](https://github.com/facebook/create-react-app/blob/main/packages/cra-template-typescript/template/README.md)
diff --git a/packages/react-scripts/template/README.md b/packages/react-scripts/template/README.md
index 1269cf81993..6aac5b05b80 100644
--- a/packages/react-scripts/template/README.md
+++ b/packages/react-scripts/template/README.md
@@ -1 +1 @@
-This file has moved [here](https://github.com/facebook/create-react-app/blob/master/packages/cra-template/template/README.md)
+This file has moved [here](https://github.com/facebook/create-react-app/blob/main/packages/cra-template/template/README.md)
diff --git a/tasks/publish.sh b/tasks/publish.sh
index f5ed3838c93..8a7b08062d9 100755
--- a/tasks/publish.sh
+++ b/tasks/publish.sh
@@ -8,7 +8,7 @@
 # This releases an update to the `react-scripts` package.
 # Don't use `npm publish` for it.
 # Read the release instructions:
-# https://github.com/facebook/create-react-app/blob/master/CONTRIBUTING.md#cutting-a-release
+# https://github.com/facebook/create-react-app/blob/main/CONTRIBUTING.md#cutting-a-release
 # ******************************************************************************
 
 # Start in tasks/ even if run from root directory