diff --git a/packages/docusaurus-theme-common/tsconfig.json b/packages/docusaurus-theme-common/tsconfig.json
index f5902ba108..8276c0b706 100644
--- a/packages/docusaurus-theme-common/tsconfig.json
+++ b/packages/docusaurus-theme-common/tsconfig.json
@@ -3,6 +3,7 @@
   "compilerOptions": {
     "incremental": true,
     "tsBuildInfoFile": "./lib/.tsbuildinfo",
+    "module": "esnext",
     "rootDir": "src",
     "outDir": "lib"
   }
diff --git a/packages/docusaurus-types/src/index.d.ts b/packages/docusaurus-types/src/index.d.ts
index 44f196ab07..0ab274f42c 100644
--- a/packages/docusaurus-types/src/index.d.ts
+++ b/packages/docusaurus-types/src/index.d.ts
@@ -63,6 +63,9 @@ export interface DocusaurusConfig {
       }
   )[];
   titleDelimiter?: string;
+  webpack?: {
+    jsLoader: 'babel' | ((isServer: boolean) => RuleSetRule);
+  };
 }
 
 /**
diff --git a/packages/docusaurus/src/commands/build.ts b/packages/docusaurus/src/commands/build.ts
index 7074f706b6..60ad1c2725 100644
--- a/packages/docusaurus/src/commands/build.ts
+++ b/packages/docusaurus/src/commands/build.ts
@@ -187,12 +187,14 @@ async function buildLocale({
         configureWebpack.bind(plugin), // The plugin lifecycle may reference `this`.
         clientConfig,
         false,
+        props.siteConfig.webpack?.jsLoader,
       );
 
       serverConfig = applyConfigureWebpack(
         configureWebpack.bind(plugin), // The plugin lifecycle may reference `this`.
         serverConfig,
         true,
+        props.siteConfig.webpack?.jsLoader,
       );
     }
   });
diff --git a/packages/docusaurus/src/commands/start.ts b/packages/docusaurus/src/commands/start.ts
index 2f045b48f1..cd025bd6d5 100644
--- a/packages/docusaurus/src/commands/start.ts
+++ b/packages/docusaurus/src/commands/start.ts
@@ -153,6 +153,7 @@ export default async function start(
         configureWebpack.bind(plugin), // The plugin lifecycle may reference `this`.
         config,
         false,
+        props.siteConfig.webpack?.jsLoader,
       );
     }
   });
diff --git a/packages/docusaurus/src/server/configValidation.ts b/packages/docusaurus/src/server/configValidation.ts
index 5eaeae0e25..60de610671 100644
--- a/packages/docusaurus/src/server/configValidation.ts
+++ b/packages/docusaurus/src/server/configValidation.ts
@@ -134,6 +134,11 @@ const ConfigSchema = Joi.object({
   tagline: Joi.string().allow(''),
   titleDelimiter: Joi.string().default('|'),
   noIndex: Joi.bool().default(false),
+  webpack: Joi.object({
+    jsLoader: Joi.alternatives()
+      .try(Joi.string().equal('babel'), Joi.function())
+      .optional(),
+  }).optional(),
 });
 
 // TODO move to @docusaurus/utils-validation
diff --git a/packages/docusaurus/src/webpack/__tests__/base.test.ts b/packages/docusaurus/src/webpack/__tests__/base.test.ts
index 588848f083..5891d03df4 100644
--- a/packages/docusaurus/src/webpack/__tests__/base.test.ts
+++ b/packages/docusaurus/src/webpack/__tests__/base.test.ts
@@ -81,6 +81,7 @@ describe('base webpack config', () => {
   const props = {
     outDir: '',
     siteDir: '',
+    siteConfig: {},
     baseUrl: '',
     generatedFilesDir: '',
     routesPaths: '',
diff --git a/packages/docusaurus/src/webpack/__tests__/utils.test.ts b/packages/docusaurus/src/webpack/__tests__/utils.test.ts
index 8244735e36..1dbde42171 100644
--- a/packages/docusaurus/src/webpack/__tests__/utils.test.ts
+++ b/packages/docusaurus/src/webpack/__tests__/utils.test.ts
@@ -5,10 +5,11 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {validate, Configuration} from 'webpack';
+import {validate, Configuration, RuleSetRule} from 'webpack';
 import path from 'path';
 
 import {
+  getCustomizableJSLoader,
   applyConfigureWebpack,
   applyConfigurePostCss,
   getFileLoaderUtils,
@@ -18,6 +19,40 @@ import {
   ConfigureWebpackFnMergeStrategy,
 } from '@docusaurus/types';
 
+describe('customize JS loader', () => {
+  test('getCustomizableJSLoader defaults to babel loader', () => {
+    expect(getCustomizableJSLoader()({isServer: true}).loader).toBe(
+      require.resolve('babel-loader'),
+    );
+    expect(getCustomizableJSLoader()({isServer: false}).loader).toBe(
+      require.resolve('babel-loader'),
+    );
+  });
+
+  test('getCustomizableJSLoader accepts loaders with preset', () => {
+    expect(getCustomizableJSLoader('babel')({isServer: true}).loader).toBe(
+      require.resolve('babel-loader'),
+    );
+    expect(getCustomizableJSLoader('babel')({isServer: false}).loader).toBe(
+      require.resolve('babel-loader'),
+    );
+  });
+
+  test('getCustomizableJSLoader allows customization', () => {
+    const customJSLoader = (isServer: boolean): RuleSetRule => ({
+      loader: 'my-fast-js-loader',
+      options: String(isServer),
+    });
+
+    expect(getCustomizableJSLoader(customJSLoader)({isServer: true})).toEqual(
+      customJSLoader(true),
+    );
+    expect(getCustomizableJSLoader(customJSLoader)({isServer: false})).toEqual(
+      customJSLoader(false),
+    );
+  });
+});
+
 describe('extending generated webpack config', () => {
   test('direct mutation on generated webpack config object', async () => {
     // fake generated webpack config
diff --git a/packages/docusaurus/src/webpack/base.ts b/packages/docusaurus/src/webpack/base.ts
index 66dae51dc7..78b15b2895 100644
--- a/packages/docusaurus/src/webpack/base.ts
+++ b/packages/docusaurus/src/webpack/base.ts
@@ -11,7 +11,7 @@ import path from 'path';
 import {Configuration} from 'webpack';
 import {Props} from '@docusaurus/types';
 import {
-  getJSLoader,
+  getCustomizableJSLoader,
   getStyleLoaders,
   getFileLoaderUtils,
   getCustomBabelConfigFilePath,
@@ -73,6 +73,7 @@ export function createBaseConfig(
   const {
     outDir,
     siteDir,
+    siteConfig,
     baseUrl,
     generatedFilesDir,
     routesPaths,
@@ -205,7 +206,7 @@ export function createBaseConfig(
           test: /\.(j|t)sx?$/,
           exclude: excludeJS,
           use: [
-            getJSLoader({
+            getCustomizableJSLoader(siteConfig.webpack?.jsLoader)({
               isServer,
               babelOptions: getCustomBabelConfigFilePath(siteDir),
             }),
diff --git a/packages/docusaurus/src/webpack/utils.ts b/packages/docusaurus/src/webpack/utils.ts
index f9eda08d13..0ecf28f45b 100644
--- a/packages/docusaurus/src/webpack/utils.ts
+++ b/packages/docusaurus/src/webpack/utils.ts
@@ -137,7 +137,7 @@ export function getBabelOptions({
 
 // Name is generic on purpose
 // we want to support multiple js loader implementations (babel + esbuild)
-export function getJSLoader({
+function getDefaultBabelLoader({
   isServer,
   babelOptions,
 }: {
@@ -150,6 +150,19 @@ export function getJSLoader({
   };
 }
 
+export const getCustomizableJSLoader = (
+  jsLoader: 'babel' | ((isServer: boolean) => RuleSetRule) = 'babel',
+) => ({
+  isServer,
+  babelOptions,
+}: {
+  isServer: boolean;
+  babelOptions?: TransformOptions | string;
+}): RuleSetRule =>
+  jsLoader === 'babel'
+    ? getDefaultBabelLoader({isServer, babelOptions})
+    : jsLoader(isServer);
+
 // TODO remove this before end of 2021?
 const warnBabelLoaderOnce = memoize(function () {
   console.warn(
@@ -163,7 +176,7 @@ const getBabelLoaderDeprecated = function getBabelLoaderDeprecated(
   babelOptions?: TransformOptions | string,
 ) {
   warnBabelLoaderOnce();
-  return getJSLoader({isServer, babelOptions});
+  return getDefaultBabelLoader({isServer, babelOptions});
 };
 
 // TODO remove this before end of 2021 ?
@@ -184,17 +197,19 @@ function getCacheLoaderDeprecated() {
  * @param configureWebpack a webpack config or a function to modify config
  * @param config initial webpack config
  * @param isServer indicates if this is a server webpack configuration
+ * @param jsLoader custom js loader config
  * @returns final/ modified webpack config
  */
 export function applyConfigureWebpack(
   configureWebpack: ConfigureWebpackFn,
   config: Configuration,
   isServer: boolean,
+  jsLoader?: 'babel' | ((isServer: boolean) => RuleSetRule),
 ): Configuration {
   // Export some utility functions
   const utils: ConfigureWebpackUtils = {
     getStyleLoaders,
-    getJSLoader,
+    getJSLoader: getCustomizableJSLoader(jsLoader),
     getBabelLoader: getBabelLoaderDeprecated,
     getCacheLoader: getCacheLoaderDeprecated,
   };
diff --git a/website/docusaurus.config.js b/website/docusaurus.config.js
index 434506fa07..5d97fae6c7 100644
--- a/website/docusaurus.config.js
+++ b/website/docusaurus.config.js
@@ -63,6 +63,16 @@ const isVersioningDisabled = !!process.env.DISABLE_VERSIONING || isI18nStaging;
       : // Production locales
         ['en', 'fr', 'ko', 'zh-CN'],
   },
+  webpack: {
+    jsLoader: (isServer) => ({
+      loader: require.resolve('esbuild-loader'),
+      options: {
+        loader: 'tsx',
+        format: isServer ? 'cjs' : undefined,
+        target: isServer ? 'node12' : 'es2017',
+      },
+    }),
+  },
   onBrokenLinks: 'throw',
   onBrokenMarkdownLinks: 'warn',
   favicon: 'img/docusaurus.ico',
diff --git a/website/package.json b/website/package.json
index c2d970fafd..871d525c81 100644
--- a/website/package.json
+++ b/website/package.json
@@ -39,6 +39,7 @@
     "@docusaurus/theme-live-codeblock": "2.0.0-beta.0",
     "clsx": "^1.1.1",
     "color": "^3.1.3",
+    "esbuild-loader": "2.13.0",
     "netlify-plugin-cache": "^1.0.3",
     "npm-to-yarn": "^1.0.0-2",
     "react": "^17.0.1",
diff --git a/yarn.lock b/yarn.lock
index 4d064e21b1..7b07d7fed3 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -8060,6 +8060,23 @@ es6-promisify@^5.0.0:
   dependencies:
     es6-promise "^4.0.3"
 
+esbuild-loader@2.13.0:
+  version "2.13.0"
+  resolved "https://registry.yarnpkg.com/esbuild-loader/-/esbuild-loader-2.13.0.tgz#f5a3602a89a3b728506ae3e1887304fffeef9270"
+  integrity sha512-gC9lML8RGkTSWG2pJVEOZRLMoIluq1Jd7OzzVkOZKMzbMDMWDhXEwXLs60n+aglnAYa9GVrD/UXjTHkM51nBsg==
+  dependencies:
+    esbuild "^0.11.19"
+    joycon "^3.0.1"
+    json5 "^2.2.0"
+    loader-utils "^2.0.0"
+    type-fest "^1.0.1"
+    webpack-sources "^2.2.0"
+
+esbuild@^0.11.19:
+  version "0.11.20"
+  resolved "https://registry.yarnpkg.com/esbuild/-/esbuild-0.11.20.tgz#7cefa1aee8b372c184e42457885f7ce5d3e62a1e"
+  integrity sha512-QOZrVpN/Yz74xfat0H6euSgn3RnwLevY1mJTEXneukz1ln9qB+ieaerRMzSeETpz/UJWsBMzRVR/andBht5WKw==
+
 escalade@^3.0.2, escalade@^3.1.1:
   version "3.1.1"
   resolved "https://registry.yarnpkg.com/escalade/-/escalade-3.1.1.tgz#d8cfdc7000965c5a0174b4a82eaa5c0552742e40"
@@ -11823,6 +11840,11 @@ joi@^17.3.0, joi@^17.4.0:
     "@sideway/formula" "^3.0.0"
     "@sideway/pinpoint" "^2.0.0"
 
+joycon@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/joycon/-/joycon-3.0.1.tgz#9074c9b08ccf37a6726ff74a18485f85efcaddaf"
+  integrity sha512-SJcJNBg32dGgxhPtM0wQqxqV0ax9k/9TaUskGDSJkSFSQOEWWvQ3zzWdGQRIUry2j1zA5+ReH13t0Mf3StuVZA==
+
 jpeg-js@^0.3.4:
   version "0.3.6"
   resolved "https://registry.yarnpkg.com/jpeg-js/-/jpeg-js-0.3.6.tgz#c40382aac9506e7d1f2d856eb02f6c7b2a98b37c"
@@ -11981,10 +12003,10 @@ json5@^1.0.1:
   dependencies:
     minimist "^1.2.0"
 
-json5@^2.1.2:
-  version "2.1.3"
-  resolved "https://registry.yarnpkg.com/json5/-/json5-2.1.3.tgz#c9b0f7fa9233bfe5807fe66fcf3a5617ed597d43"
-  integrity sha512-KXPvOm8K9IJKFM0bmdn8QXh7udDh1g/giieX0NLCaMnb4hEiVFqnop2ImTXCc5e0/oHz3LTqmHGtExn5hfMkOA==
+json5@^2.1.2, json5@^2.2.0:
+  version "2.2.0"
+  resolved "https://registry.yarnpkg.com/json5/-/json5-2.2.0.tgz#2dfefe720c6ba525d9ebd909950f0515316c89a3"
+  integrity sha512-f+8cldu7X/y7RAJurMEJmdoKXGB/X550w2Nr3tTbezL6RwEE/iMcm+tZnXeoZtKuOq6ft8+CqzEkrIgx1fPoQA==
   dependencies:
     minimist "^1.2.5"
 
@@ -19210,6 +19232,11 @@ type-fest@^0.8.0, type-fest@^0.8.1:
   resolved "https://registry.yarnpkg.com/type-fest/-/type-fest-0.8.1.tgz#09e249ebde851d3b1e48d27c105444667f17b83d"
   integrity sha512-4dbzIzqvjtgiM5rw1k5rEHtBANKmdudhGyBEajN01fEyhaAIhsoKNy6y7+IN93IfpFtwY9iqi7kD+xwKhQsNJA==
 
+type-fest@^1.0.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/type-fest/-/type-fest-1.1.1.tgz#210251e7f57357a1457269e6b34837fed067ac2c"
+  integrity sha512-RPDKc5KrIyKTP7Fk75LruUagqG6b+OTgXlCR2Z0aQDJFeIvL4/mhahSEtHmmVzXu4gmA0srkF/8FCH3WOWxTWA==
+
 type-is@~1.6.17, type-is@~1.6.18:
   version "1.6.18"
   resolved "https://registry.yarnpkg.com/type-is/-/type-is-1.6.18.tgz#4e552cd05df09467dcbc4ef739de89f2cf37c131"
@@ -19996,7 +20023,7 @@ webpack-sources@^1.1.0, webpack-sources@^1.4.3:
     source-list-map "^2.0.0"
     source-map "~0.6.1"
 
-webpack-sources@^2.1.1:
+webpack-sources@^2.1.1, webpack-sources@^2.2.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/webpack-sources/-/webpack-sources-2.2.0.tgz#058926f39e3d443193b6c31547229806ffd02bac"
   integrity sha512-bQsA24JLwcnWGArOKUxYKhX3Mz/nK1Xf6hxullKERyktjNMC4x8koOeaDNTA2fEJ09BdWLbM/iTW0ithREUP0w==