[![npm][npm]][npm-url] [![node][node]][node-url] [![tests][tests]][tests-url] [![cover][cover]][cover-url] [![discussion][discussion]][discussion-url] [![size][size]][size-url] # terser-webpack-plugin This plugin uses [terser](https://github.com/terser/terser) to minify/minimize your JavaScript. ## Getting Started Webpack v5 comes with the latest `terser-webpack-plugin` out of the box. If you are using Webpack v5 or above and wish to customize the options, you will still need to install `terser-webpack-plugin`. Using Webpack v4, you have to install `terser-webpack-plugin` v4. To begin, you'll need to install `terser-webpack-plugin`: ```console npm install terser-webpack-plugin --save-dev ``` or ```console yarn add -D terser-webpack-plugin ``` or ```console pnpm add -D terser-webpack-plugin ``` Then add the plugin to your `webpack` configuration. For example: **webpack.config.js** ```js const TerserPlugin = require("terser-webpack-plugin"); module.exports = { optimization: { minimize: true, minimizer: [new TerserPlugin()], }, }; ``` Finally, run `webpack` using the method you normally use (e.g., via CLI or an npm script). ## Note about source maps **Works only with `source-map`, `inline-source-map`, `hidden-source-map` and `nosources-source-map` values for the [`devtool`](https://webpack.js.org/configuration/devtool/) option.** Why? - `eval` wraps modules in `eval("string")` and the minimizer does not handle strings. - `cheap` has no column information and the minimizer generates only a single line, which leaves only a single mapping. Using supported `devtool` values enable source map generation. ## Options - **[`test`](#test)** - **[`include`](#include)** - **[`exclude`](#exclude)** - **[`parallel`](#parallel)** - **[`minify`](#minify)** - **[`terserOptions`](#terseroptions)** - **[`extractComments`](#extractcomments)** ### `test` Type: ```ts type test = string | RegExp | (string | RegExp)[]; ``` Default: `/\.m?js(\?.*)?$/i` Test to match files against. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ test: /\.js(\?.*)?$/i, }), ], }, }; ``` ### `include` Type: ```ts type include = string | RegExp | (string | RegExp)[]; ``` Default: `undefined` Files to include. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ include: /\/includes/, }), ], }, }; ``` ### `exclude` Type: ```ts type exclude = string | RegExp | (string | RegExp)[]; ``` Default: `undefined` Files to exclude. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ exclude: /\/excludes/, }), ], }, }; ``` ### `parallel` Type: ```ts type parallel = boolean | number; ``` Default: `true` Use multi-process parallel running to improve the build speed. Default number of concurrent runs: `os.cpus().length - 1` or `os.availableParallelism() - 1` (if this function is supported). > **Note** > > Parallelization can speedup your build significantly and is therefore **highly recommended**. > **Warning** > > If you use **Circle CI** or any other environment that doesn't provide the real available count of CPUs then you need to explicitly set up the number of CPUs to avoid `Error: Call retries were exceeded` (see [#143](https://github.com/webpack/terser-webpack-plugin/issues/143), [#202](https://github.com/webpack/terser-webpack-plugin/issues/202)). #### `boolean` Enable/disable multi-process parallel running. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ parallel: true, }), ], }, }; ``` #### `number` Enable multi-process parallel running and set number of concurrent runs. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ parallel: 4, }), ], }, }; ``` ### `minify` Type: ```ts type minify = ( input: Record, sourceMap: import("@jridgewell/trace-mapping").SourceMapInput | undefined, minifyOptions: { module?: boolean | undefined; ecma?: import("terser").ECMA | undefined; }, extractComments: | boolean | "all" | "some" | RegExp | (( astNode: any, comment: { value: string; type: "comment1" | "comment2" | "comment3" | "comment4"; pos: number; line: number; col: number; }, ) => boolean) | { condition?: | boolean | "all" | "some" | RegExp | (( astNode: any, comment: { value: string; type: "comment1" | "comment2" | "comment3" | "comment4"; pos: number; line: number; col: number; }, ) => boolean) | undefined; filename?: string | ((fileData: any) => string) | undefined; banner?: | string | boolean | ((commentsFile: string) => string) | undefined; } | undefined, ) => Promise<{ code: string; map?: import("@jridgewell/trace-mapping").SourceMapInput | undefined; errors?: (string | Error)[] | undefined; warnings?: (string | Error)[] | undefined; extractedComments?: string[] | undefined; }>; ``` Default: `TerserPlugin.terserMinify` Allows you to override the default minify function. By default plugin uses [terser](https://github.com/terser/terser) package. Useful for using and testing unpublished versions or forks. > **Warning** > > **Always use `require` inside `minify` function when `parallel` option enabled**. **webpack.config.js** ```js // Can be async const minify = (input, sourceMap, minimizerOptions, extractsComments) => { // The `minimizerOptions` option contains option from the `terserOptions` option // You can use `minimizerOptions.myCustomOption` // Custom logic for extract comments const { map, code } = require("uglify-module") // Or require('./path/to/uglify-module') .minify(input, { /* Your options for minification */ }); return { map, code, warnings: [], errors: [], extractedComments: [] }; }; // Used to regenerate `fullhash`/`chunkhash` between different implementation // Example: you fix a bug in custom minimizer/custom function, but unfortunately webpack doesn't know about it, so you will get the same fullhash/chunkhash // to avoid this you can provide version of your custom minimizer // You don't need if you use only `contenthash` minify.getMinimizerVersion = () => { let packageJson; try { packageJson = require("uglify-module/package.json"); } catch (error) { // Ignore } return packageJson && packageJson.version; }; module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ terserOptions: { myCustomOption: true, }, minify, }), ], }, }; ``` ### `terserOptions` Type: ```ts interface terserOptions { compress?: boolean | CompressOptions; ecma?: ECMA; enclose?: boolean | string; ie8?: boolean; keep_classnames?: boolean | RegExp; keep_fnames?: boolean | RegExp; mangle?: boolean | MangleOptions; module?: boolean; nameCache?: object; format?: FormatOptions; /** @deprecated */ output?: FormatOptions; parse?: ParseOptions; safari10?: boolean; sourceMap?: boolean | SourceMapOptions; toplevel?: boolean; } ``` Default: [default](https://github.com/terser/terser#minify-options) Terser [options](https://github.com/terser/terser#minify-options). **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ terserOptions: { ecma: undefined, parse: {}, compress: {}, mangle: true, // Note `mangle.properties` is `false` by default. module: false, // Deprecated output: null, format: null, toplevel: false, nameCache: null, ie8: false, keep_classnames: undefined, keep_fnames: false, safari10: false, }, }), ], }, }; ``` ### `extractComments` Type: ```ts type extractComments = | boolean | string | RegExp | (( astNode: any, comment: { value: string; type: "comment1" | "comment2" | "comment3" | "comment4"; pos: number; line: number; col: number; }, ) => boolean) | { condition?: | boolean | "all" | "some" | RegExp | (( astNode: any, comment: { value: string; type: "comment1" | "comment2" | "comment3" | "comment4"; pos: number; line: number; col: number; }, ) => boolean) | undefined; filename?: string | ((fileData: any) => string) | undefined; banner?: | string | boolean | ((commentsFile: string) => string) | undefined; }; ``` Default: `true` Whether comments shall be extracted to a separate file, (see [details](https://github.com/webpack/webpack/commit/71933e979e51c533b432658d5e37917f9e71595a)). By default, extract only comments using `/^\**!|@preserve|@license|@cc_on/i` RegExp condition and remove remaining comments. If the original file is named `foo.js`, then the comments will be stored to `foo.js.LICENSE.txt`. The `terserOptions.format.comments` option specifies whether the comment will be preserved - i.e., it is possible to preserve some comments (e.g. annotations) while extracting others, or even preserve comments that have already been extracted. #### `boolean` Enable/disable extracting comments. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ extractComments: true, }), ], }, }; ``` #### `string` Extract `all` or `some` (use the `/^\**!|@preserve|@license|@cc_on/i` RegExp) comments. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ extractComments: "all", }), ], }, }; ``` #### `RegExp` All comments that match the given expression will be extracted to a separate file. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ extractComments: /@extract/i, }), ], }, }; ``` #### `function` All comments that match the given expression will be extracted to a separate file. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ extractComments: (astNode, comment) => { if (/@extract/i.test(comment.value)) { return true; } return false; }, }), ], }, }; ``` #### `object` Allows you to customize condition for extracting comments, and specify the extracted file name and banner. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ extractComments: { condition: /^\**!|@preserve|@license|@cc_on/i, filename: (fileData) => // The "fileData" argument contains object with "filename", "basename", "query" and "hash" `${fileData.filename}.LICENSE.txt${fileData.query}`, banner: (licenseFile) => `License information can be found in ${licenseFile}`, }, }), ], }, }; ``` ##### `condition` Type: ```ts type condition = | boolean | "all" | "some" | RegExp | (( astNode: any, comment: { value: string; type: "comment1" | "comment2" | "comment3" | "comment4"; pos: number; line: number; col: number; }, ) => boolean) | undefined; ``` The condition that determines which comments should be extracted. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ extractComments: { condition: "some", filename: (fileData) => // The "fileData" argument contains object with "filename", "basename", "query" and "hash" `${fileData.filename}.LICENSE.txt${fileData.query}`, banner: (licenseFile) => `License information can be found in ${licenseFile}`, }, }), ], }, }; ``` ##### `filename` Type: ```ts type filename = string | ((fileData: any) => string) | undefined; ``` Default: `[file].LICENSE.txt[query]` Available placeholders: `[file]`, `[query]` and `[filebase]` (`[base]` for webpack 5). The file where the extracted comments will be stored. Default is to append the suffix `.LICENSE.txt` to the original filename. > **Warning** > > We highly recommend using the `.txt` extension. Using `.js`/`.cjs`/`.mjs` extensions may conflict with existing assets, which leads to broken code. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ extractComments: { condition: /^\**!|@preserve|@license|@cc_on/i, filename: "extracted-comments.js", banner: (licenseFile) => `License information can be found in ${licenseFile}`, }, }), ], }, }; ``` ##### `banner` Type: ```ts type banner = string | boolean | ((commentsFile: string) => string) | undefined; ``` Default: `/*! For license information please see ${commentsFile} */` The banner text that points to the extracted file and will be added at the top of the original file. It can be `false` (no banner), a `String`, or a `function<(string) -> String>` that will be called with the filename where the extracted comments have been stored. The banner will be wrapped in a comment. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ extractComments: { condition: true, filename: (fileData) => // The "fileData" argument contains object with "filename", "basename", "query" and "hash" `${fileData.filename}.LICENSE.txt${fileData.query}`, banner: (commentsFile) => `My custom banner about license information ${commentsFile}`, }, }), ], }, }; ``` ## Examples ### Preserve Comments Extract all legal comments (i.e. `/^\**!|@preserve|@license|@cc_on/i`) and preserve `/@license/i` comments. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ terserOptions: { format: { comments: /@license/i, }, }, extractComments: true, }), ], }, }; ``` ### Remove Comments If you want to build without comments, use this config: **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ terserOptions: { format: { comments: false, }, }, extractComments: false, }), ], }, }; ``` ### [`uglify-js`](https://github.com/mishoo/UglifyJS) [`UglifyJS`](https://github.com/mishoo/UglifyJS) is a JavaScript parser, minifier, compressor and beautifier toolkit. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ minify: TerserPlugin.uglifyJsMinify, // `terserOptions` options will be passed to `uglify-js` // Link to options - https://github.com/mishoo/UglifyJS#minify-options terserOptions: {}, }), ], }, }; ``` ### [`swc`](https://github.com/swc-project/swc) [`swc`](https://github.com/swc-project/swc) is a super-fast compiler written in `Rust`, producing widely supported JavaScript from modern standards and TypeScript. > **Warning** > > The `extractComments` option is not supported, and all comments will be removed by default. This will be fixed in future **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ minify: TerserPlugin.swcMinify, // `terserOptions` options will be passed to `swc` (`@swc/core`) // Link to options - https://swc.rs/docs/config-js-minify terserOptions: {}, }), ], }, }; ``` ### [`esbuild`](https://github.com/evanw/esbuild) [`esbuild`](https://github.com/evanw/esbuild) is an extremely fast JavaScript bundler and minifier. > **Warning** > > The `extractComments` option is not supported, and all legal comments (i.e. copyright, licenses and etc) will be preserved. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ minify: TerserPlugin.esbuildMinify, // `terserOptions` options will be passed to `esbuild` // Link to options - https://esbuild.github.io/api/#minify // Note: the `minify` options is true by default (and override other `minify*` options), so if you want to disable the `minifyIdentifiers` option (or other `minify*` options) please use: // terserOptions: { // minify: false, // minifyWhitespace: true, // minifyIdentifiers: false, // minifySyntax: true, // }, terserOptions: {}, }), ], }, }; ``` ### Custom Minify Function Override the default minify function - use `uglify-js` for minification. **webpack.config.js** ```js module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ minify: (file, sourceMap) => { // https://github.com/mishoo/UglifyJS2#minify-options const uglifyJsOptions = { /* your `uglify-js` package options */ }; if (sourceMap) { uglifyJsOptions.sourceMap = { content: sourceMap, }; } return require("uglify-js").minify(file, uglifyJsOptions); }, }), ], }, }; ``` ### Typescript With default Terser minify function: ```ts module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ terserOptions: { compress: true, }, }), ], }, }; ``` With built-in minify functions: ```ts import { type JsMinifyOptions as SwcOptions } from "@swc/core"; import { type TransformOptions as EsbuildOptions } from "esbuild"; import { type MinifyOptions as TerserOptions } from "terser"; import { type MinifyOptions as UglifyJSOptions } from "uglify-js"; module.exports = { optimization: { minimize: true, minimizer: [ new TerserPlugin({ minify: TerserPlugin.swcMinify, terserOptions: { // `swc` options }, }), new TerserPlugin({ minify: TerserPlugin.uglifyJsMinify, terserOptions: { // `uglif-js` options }, }), new TerserPlugin({ minify: TerserPlugin.esbuildMinify, terserOptions: { // `esbuild` options }, }), // Alternative usage: new TerserPlugin({ minify: TerserPlugin.terserMinify, terserOptions: { // `terser` options }, }), ], }, }; ``` ## Contributing We welcome all contributions! If you're new here, please take a moment to review our contributing guidelines before submitting issues or pull requests. [CONTRIBUTING](https://github.com/webpack/terser-webpack-plugin?tab=contributing-ov-file#contributing) ## License [MIT](./LICENSE) [npm]: https://img.shields.io/npm/v/terser-webpack-plugin.svg [npm-url]: https://npmjs.com/package/terser-webpack-plugin [node]: https://img.shields.io/node/v/terser-webpack-plugin.svg [node-url]: https://nodejs.org [tests]: https://github.com/webpack/terser-webpack-plugin/workflows/terser-webpack-plugin/badge.svg [tests-url]: https://github.com/webpack/terser-webpack-plugin/actions [cover]: https://codecov.io/gh/webpack/terser-webpack-plugin/branch/main/graph/badge.svg [cover-url]: https://codecov.io/gh/webpack/terser-webpack-plugin [discussion]: https://img.shields.io/github/discussions/webpack/webpack [discussion-url]: https://github.com/webpack/webpack/discussions [size]: https://packagephobia.now.sh/badge?p=terser-webpack-plugin [size-url]: https://packagephobia.now.sh/result?p=terser-webpack-plugin