v6.0.0

Major Changes

• Bump Express to v5. See the Express 5 migration guide for the full list of breaking changes. (by @bjohansebas in #5674)

• Bump the webpack peer dependency range from ^5.0.0 to ^5.101.0. (by @bjohansebas in #5674)

• Drop support for Node.js < 22.15.0. (by @bjohansebas in #5674)

• 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. (by @bjohansebas in #5674)

• Remove CLI flags. Use the serve command from webpack-cli together with a configuration file or the programmatic API instead. (by @bjohansebas in #5674)

• Remove the internalIP and internalIPSync static methods from Server. Resolve the local IP yourself if you need it. (by @bjohansebas in #5674)

• Remove the bypass option from proxy configuration. Use the router or context options provided by http-proxy-middleware instead. (by @bjohansebas in #5674)

• Remove SockJS support. The webSocketServer option no longer accepts "sockjs"; use the default "ws" transport instead. (by @bjohansebas in #5674)

• Remove the spdy dependency. Use the built-in node:http2 module via the server option for HTTP/2 support. (by @bjohansebas in #5674)

• Update http-proxy-middleware to v4. See the http-proxy-middleware v3 release notes and v4 release notes for the full list of breaking changes. (by @bjohansebas in #5674)

• Update webpack-dev-middleware to v8 and sync originalUrl for middleware compatibility. server.middleware.getFilenameFromUrl() is now asynchronous and resolves to { filename, extra: { stats, outputFileSystem } }. See the webpack-dev-middleware v8 release notes for details. (by @bjohansebas in #5674)

Minor Changes

• Add plugin support. webpack-dev-server can now be used as a webpack plugin, integrating with the compiler lifecycle without explicitly passing a compiler, preventing multiple server starts on recompilation, ensuring clean shutdown, and supporting MultiCompiler setups with multiple independent plugin servers. (by @bjohansebas in #5674)

• Enable the compression middleware for HTTP/2 connections. (by @bjohansebas in #5674)

• Remove the colorette dependency in favor of native ANSI styling. (by @bjohansebas in #5674)

• Update chokidar to v5 and extend watchFiles.options.ignored to support glob string patterns via tinyglobby. (by @bjohansebas in #5674)

• Use compiler.platform to determine the target environment instead of inspecting the resolved target string. Universal targets ("universal" or ["web", "node"], where compiler.platform.universal is true since webpack 5.108.0) are treated as web targets so the client runtime is injected. (by @bjohansebas in #5674)

• Use the WHATWG URL API instead of the deprecated url.parse. (by @bjohansebas in #5674)

Patch Changes

• Bump production dependencies, notably open to v11 and p-retry to v8. (by @bjohansebas in #5674)

• Reject cross-site requests to the internal open-editor and invalidate endpoints. They performed state-changing actions (opening a file in the editor, forcing a recompilation) on any GET request, so a page the developer visited could trigger them. They now require a same-origin request, validated via Sec-Fetch-Site with an Origin/Host fallback. (by @bjohansebas in #5691)

• Treat loopback aliases (127.0.0.1, ::1, localhost) as equivalent in isSameOrigin so the WebSocket client does not reject valid same-origin connections. (by @bjohansebas in #5674)

• Migrate the test suite from Jest to node:test and set up the jsdom environment. (by @bjohansebas in #5674)

• Update webpack-cli to v7.0.2. (by @bjohansebas in #5674)