diff --git a/.changeset/migrate-to-esm.md b/.changeset/migrate-to-esm.md
index ce9a39ffdf..2a50601837 100644
--- a/.changeset/migrate-to-esm.md
+++ b/.changeset/migrate-to-esm.md
@@ -2,4 +2,4 @@
 "webpack-dev-server": major
 ---
 
-Migrate the package to ES module syntax. The package is now published as ESM-only.
+Convert the source to native ES modules. The package keeps `"type": "module"` and now exposes both an ESM and a CommonJS build via the `exports` field: ESM consumers `import` the native `lib/`, while CommonJS consumers `require()` a transpiled `dist/` build — so the package works from both ESM and CommonJS, including environments where `require(ESM)` is not supported.
diff --git a/.gitignore b/.gitignore
index 8a1aee341d..bf65d04489 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,6 +9,7 @@ client
 !/test/client
 
 examples/**/dist
+dist
 
 coverage
 node_modules
diff --git a/babel.config.js b/babel.config.js
index 49ff61255b..04964c2cdd 100644
--- a/babel.config.js
+++ b/babel.config.js
@@ -1,5 +1,30 @@
 export default (api) => {
-  api.cache(true);
+  // `api.env()` makes the resolved config cache depend on `BABEL_ENV`/`NODE_ENV`
+  // so the `cjs` build and the default client build don't share a cache entry.
+  const env = api.env();
+
+  // CommonJS build (`build:cjs`, `babel --env-name cjs`). `lib/` is authored as
+  // native ESM; here we transpile it to CJS for the dual package. `preset-env`
+  // with `modules: "commonjs"` rewrites `import()` into real `require()` (the
+  // target environments don't reliably support `require(ESM)`), and
+  // `babel-plugin-transform-import-meta` rewrites `import.meta.url` (used by
+  // `createRequire`) for CJS.
+  if (env === "cjs") {
+    return {
+      presets: [
+        [
+          "@babel/preset-env",
+          {
+            modules: "commonjs",
+            targets: {
+              node: "22.15.0",
+            },
+          },
+        ],
+      ],
+      plugins: ["babel-plugin-transform-import-meta"],
+    };
+  }
 
   return {
     presets: [
diff --git a/eslint.config.mjs b/eslint.config.mjs
index bb93d5feb3..57c7d43337 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -3,7 +3,7 @@ import config from "eslint-config-webpack";
 import configs from "eslint-config-webpack/configs.js";
 
 export default defineConfig([
-  globalIgnores(["client/**/*", "examples/**/*"]),
+  globalIgnores(["client/**/*", "dist/**/*", "examples/**/*"]),
   {
     extends: [config],
     ignores: ["client-src/**/*", "!client-src/webpack.config.js"],
diff --git a/lib/Server.js b/lib/Server.js
index bedba64ad3..8c3335858a 100644
--- a/lib/Server.js
+++ b/lib/Server.js
@@ -1,13 +1,16 @@
 import { createRequire } from "node:module";
 import os from "node:os";
 import path from "node:path";
-import url, { fileURLToPath } from "node:url";
+import url from "node:url";
 import fs from "graceful-fs";
 import ipaddr from "ipaddr.js";
 import { validate } from "schema-utils";
 import schema from "./options.json" with { type: "json" };
 
-const require = createRequire(import.meta.url);
+// Named `cjsRequire` (not `require`) so it doesn't shadow the implicit CommonJS
+// `require` in the transpiled `dist/cjs` build, which would collide with the
+// `require("url")` that `babel-plugin-transform-import-meta` injects here.
+const cjsRequire = createRequire(import.meta.url);
 
 /** @type {Promise<typeof import("webpack") | undefined> | undefined} */
 let webpackPeer;
@@ -1498,12 +1501,12 @@ class Server {
       case "string":
         // could be 'ws', or a path that should be resolved
         if (clientTransport === "ws") {
-          clientImplementation = fileURLToPath(
-            import.meta.resolve("../client/clients/WebSocketClient.js"),
+          clientImplementation = cjsRequire.resolve(
+            "../client/clients/WebSocketClient.js",
           );
         } else {
           try {
-            clientImplementation = require.resolve(clientTransport);
+            clientImplementation = cjsRequire.resolve(clientTransport);
           } catch {
             clientImplementationFound = false;
           }
@@ -1552,7 +1555,7 @@ class Server {
             .default;
         } else {
           try {
-            const mod = require(
+            const mod = cjsRequire(
               /** @type {string} */ (
                 /** @type {WebSocketServerConfiguration} */
                 (this.options.webSocketServer).type
@@ -1590,7 +1593,7 @@ class Server {
    */
 
   getClientEntry() {
-    return fileURLToPath(import.meta.resolve("../client/index.js"));
+    return cjsRequire.resolve("../client/index.js");
   }
 
   /**
@@ -1598,9 +1601,9 @@ class Server {
    */
   getClientHotEntry() {
     if (this.options.hot === "only") {
-      return fileURLToPath(import.meta.resolve("webpack/hot/only-dev-server"));
+      return cjsRequire.resolve("webpack/hot/only-dev-server");
     } else if (this.options.hot) {
-      return fileURLToPath(import.meta.resolve("webpack/hot/dev-server"));
+      return cjsRequire.resolve("webpack/hot/dev-server");
     }
   }
 
@@ -2455,7 +2458,7 @@ class Server {
         (this.app),
       );
     } else {
-      const mod = require(/** @type {string} */ (type));
+      const mod = cjsRequire(/** @type {string} */ (type));
 
       const serverType = mod.default || mod;
 
diff --git a/package-lock.json b/package-lock.json
index 4f602a8409..ac22c0e452 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -60,6 +60,7 @@
         "@types/trusted-types": "^2.0.7",
         "acorn": "^8.14.0",
         "babel-loader": "^10.0.0",
+        "babel-plugin-transform-import-meta": "^2.3.3",
         "connect": "^3.7.0",
         "core-js": "^3.38.1",
         "cspell": "^8.15.5",
@@ -6091,6 +6092,20 @@
         "@babel/core": "^7.4.0 || ^8.0.0-0 <8.0.0"
       }
     },
+    "node_modules/babel-plugin-transform-import-meta": {
+      "version": "2.3.3",
+      "resolved": "https://registry.npmjs.org/babel-plugin-transform-import-meta/-/babel-plugin-transform-import-meta-2.3.3.tgz",
+      "integrity": "sha512-bbh30qz1m6ZU1ybJoNOhA2zaDvmeXMnGNBMVMDOJ1Fni4+wMBoy/j7MTRVmqAUCIcy54/rEnr9VEBsfcgbpm3Q==",
+      "dev": true,
+      "license": "BSD-3-Clause",
+      "dependencies": {
+        "@babel/template": "^7.25.9",
+        "tslib": "^2.8.1"
+      },
+      "peerDependencies": {
+        "@babel/core": "^7.10.0"
+      }
+    },
     "node_modules/balanced-match": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-1.0.2.tgz",
diff --git a/package.json b/package.json
index 67aa272f68..eff66f622c 100644
--- a/package.json
+++ b/package.json
@@ -12,12 +12,24 @@
   "license": "MIT",
   "author": "Tobias Koppers @sokra",
   "type": "module",
-  "main": "lib/Server.js",
+  "exports": {
+    ".": {
+      "types": "./types/lib/Server.d.ts",
+      "import": "./lib/Server.js",
+      "require": "./dist/Server.js",
+      "default": "./lib/Server.js"
+    },
+    "./client/*": "./client/*",
+    "./package.json": "./package.json"
+  },
+  "main": "./dist/Server.js",
+  "module": "./lib/Server.js",
   "types": "types/lib/Server.d.ts",
   "bin": "bin/webpack-dev-server.js",
   "files": [
     "bin",
     "lib",
+    "dist",
     "client",
     "types"
   ],
@@ -34,6 +46,7 @@
     "fix": "npm-run-all -l fix:code fix:prettier",
     "commitlint": "commitlint --from=main",
     "validate:changeset": "node .changeset/changeset-validate.mjs",
+    "build:cjs": "rimraf -g ./dist/* && babel lib --out-dir dist --env-name cjs --copy-files --no-copy-ignored && node ./scripts/finalize-cjs-build.mjs",
     "build:client": "rimraf -g ./client/* && babel client-src/ --out-dir client/ --ignore \"client-src/webpack.config.js\" --ignore \"client-src/modules\" && webpack --config client-src/webpack.config.js",
     "build:types": "rimraf -g ./types/* && tsc --declaration --emitDeclarationOnly --outDir types && node ./scripts/extend-webpack-types.js && prettier \"types/**/*.ts\" --write && prettier \"types/**/*.ts\" --write",
     "build": "npm-run-all -p \"build:**\"",
@@ -93,6 +106,7 @@
     "@types/trusted-types": "^2.0.7",
     "acorn": "^8.14.0",
     "babel-loader": "^10.0.0",
+    "babel-plugin-transform-import-meta": "^2.3.3",
     "connect": "^3.7.0",
     "core-js": "^3.38.1",
     "cspell": "^8.15.5",
diff --git a/scripts/finalize-cjs-build.mjs b/scripts/finalize-cjs-build.mjs
new file mode 100644
index 0000000000..ef4b61c818
--- /dev/null
+++ b/scripts/finalize-cjs-build.mjs
@@ -0,0 +1,33 @@
+import { appendFile, writeFile } from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+// Finalize the CommonJS build produced by `babel lib --out-dir dist`.
+//
+// The CJS build is emitted flat into `dist/` (same depth from the package root
+// as `lib/`) so the relative `cjsRequire.resolve("../client/...")` calls in
+// `Server.js` resolve to `<root>/client` from both `lib/` and `dist/`.
+//
+// 1. Drop a `package.json` with `"type": "commonjs"` so Node treats the `.js`
+//    files in `dist/` as CommonJS regardless of the package's root
+//    `"type": "module"`.
+// 2. Babel emits the loader as `exports.default`. Append the `module.exports`
+//    unwrap so `require("webpack-dev-server")` returns the `Server` class
+//    directly (parity with the pre-ESM `module.exports = Server`), while
+//    `.default` keeps pointing at it for interop.
+
+const CJS_DIR = path.resolve(
+  path.dirname(fileURLToPath(import.meta.url)),
+  "..",
+  "dist",
+);
+
+await writeFile(
+  path.join(CJS_DIR, "package.json"),
+  `${JSON.stringify({ type: "commonjs" }, null, 2)}\n`,
+);
+
+await appendFile(
+  path.join(CJS_DIR, "Server.js"),
+  "module.exports = exports.default;\nmodule.exports.default = exports.default;\n",
+);
diff --git a/test/cjs.test.js b/test/cjs.test.js
new file mode 100644
index 0000000000..c60e53decb
--- /dev/null
+++ b/test/cjs.test.js
@@ -0,0 +1,145 @@
+import {
+  appendFileSync,
+  copyFileSync,
+  mkdirSync,
+  mkdtempSync,
+  readFileSync,
+  readdirSync,
+  rmSync,
+  writeFileSync,
+} from "node:fs";
+import { createRequire } from "node:module";
+import path from "node:path";
+import { after, before, describe, it } from "node:test";
+import { fileURLToPath } from "node:url";
+import { transformFileAsync } from "@babel/core";
+import { expect } from "expect";
+import Server from "../lib/Server.js";
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const rootDir = path.join(__dirname, "..");
+const libDir = path.join(rootDir, "lib");
+
+const require = createRequire(import.meta.url);
+
+/**
+ * Collect every file under `dir` recursively.
+ * @param {string} dir directory to walk
+ * @returns {string[]} absolute file paths
+ */
+function walk(dir) {
+  const files = [];
+
+  for (const entry of readdirSync(dir, { withFileTypes: true })) {
+    const full = path.join(dir, entry.name);
+
+    if (entry.isDirectory()) {
+      files.push(...walk(full));
+    } else {
+      files.push(full);
+    }
+  }
+
+  return files;
+}
+
+/**
+ * Reproduce the `build:cjs` pipeline against `lib/` into `outDir`: transpile
+ * every `.js` file with Babel's `cjs` env, copy other assets, drop the
+ * `package.json` CommonJS marker and append the `module.exports = exports.default`
+ * unwrap that `scripts/finalize-cjs-build.mjs` writes. The result can then be
+ * `require()`d directly.
+ * @param {string} outDir target directory
+ */
+async function buildCjsBundle(outDir) {
+  for (const source of walk(libDir)) {
+    const target = path.join(outDir, path.relative(libDir, source));
+
+    mkdirSync(path.dirname(target), { recursive: true });
+
+    if (source.endsWith(".js")) {
+      const result = await transformFileAsync(source, { envName: "cjs" });
+
+      writeFileSync(target, result.code);
+    } else {
+      copyFileSync(source, target);
+    }
+  }
+
+  writeFileSync(
+    path.join(outDir, "package.json"),
+    `${JSON.stringify({ type: "commonjs" }, null, 2)}\n`,
+  );
+
+  appendFileSync(
+    path.join(outDir, "Server.js"),
+    "module.exports = exports.default;\nmodule.exports.default = exports.default;\n",
+  );
+}
+
+describe("cjs", () => {
+  let bundleDir;
+  let serverPath;
+  let serverSource;
+  let bundlePackage;
+  let cjsServer;
+
+  before(async () => {
+    // Build inside `node_modules` so the transpiled bare `require()`s
+    // (`schema-utils`, `graceful-fs`, ...) resolve against the project deps.
+    bundleDir = mkdtempSync(path.join(rootDir, "node_modules", ".wds-cjs-"));
+
+    await buildCjsBundle(bundleDir);
+
+    serverPath = path.join(bundleDir, "Server.js");
+    serverSource = readFileSync(serverPath, "utf8");
+    bundlePackage = JSON.parse(
+      readFileSync(path.join(bundleDir, "package.json"), "utf8"),
+    );
+    cjsServer = require(serverPath);
+  });
+
+  after(() => {
+    if (bundleDir) {
+      rmSync(bundleDir, { recursive: true, force: true });
+    }
+  });
+
+  it("should produce a require()-able CommonJS bundle", () => {
+    expect(bundlePackage.type).toBe("commonjs");
+
+    // Babel's strict-mode prologue, the `exports.default` assignment and the
+    // unwrap appended by the finalize step.
+    expect(serverSource).toMatch(/^"use strict";/);
+    expect(serverSource).toMatch(/exports\.default = /);
+    expect(serverSource).toMatch(/module\.exports = exports\.default;/);
+
+    // No executable dynamic `import()` or `import.meta` survives in the CJS
+    // build. Strip comments first since JSDoc type annotations legitimately
+    // reference `import("pkg")` and `[S=import("http").Server]`.
+    const executableCode = serverSource
+      .replaceAll(/\/\*[\s\S]*?\*\//g, "")
+      .replaceAll(/^\s*\/\/.*$/gm, "");
+
+    expect(executableCode).not.toMatch(/import\(/);
+    expect(executableCode).not.toMatch(/import\.meta/);
+  });
+
+  it("should expose the Server class through `require` (pre-ESM shape)", () => {
+    // `require("webpack-dev-server")` returns the class directly, with
+    // `.default` pointing back at it for ESM interop.
+    expect(typeof cjsServer).toBe("function");
+    expect(cjsServer.default).toBe(cjsServer);
+    expect(cjsServer.name).toBe(Server.name);
+    expect(cjsServer.length).toBe(Server.length);
+  });
+
+  it("should match the ESM default export", () => {
+    expect(typeof Server).toBe("function");
+    expect(cjsServer.name).toBe("Server");
+    // Same public statics/prototype surface as the ESM build.
+    expect(Object.getOwnPropertyNames(cjsServer.prototype)).toEqual(
+      Object.getOwnPropertyNames(Server.prototype),
+    );
+  });
+});