terser-webpack-plugin
Advanced tools
This plugin uses terser to minify/minimize your JavaScript.
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:
npm install terser-webpack-plugin --save-dev
or
yarn add -D terser-webpack-plugin
or
pnpm add -D terser-webpack-plugin
Then add the plugin to your webpack configuration. For example:
webpack.config.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).
Works only with source-map, inline-source-map, hidden-source-map and nosources-source-map values for the 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.
testType:
type test = string | RegExp | (string | RegExp)[];
Default: /\.m?js(\?.*)?$/i
Test to match files against.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
test: /\.js(\?.*)?$/i,
}),
],
},
};
includeType:
type include = string | RegExp | (string | RegExp)[];
Default: undefined
Files to include.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
include: /\/includes/,
}),
],
},
};
excludeType:
type exclude = string | RegExp | (string | RegExp)[];
Default: undefined
Files to exclude.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
exclude: /\/excludes/,
}),
],
},
};
parallelType:
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, #202).
booleanEnable/disable multi-process parallel running.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
parallel: true,
}),
],
},
};
numberEnable multi-process parallel running and set number of concurrent runs.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
parallel: 4,
}),
],
},
};
minifyType:
type minify = (
input: Record<string, string>,
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 package. Useful for using and testing unpublished versions or forks.
Warning
Always use
requireinsideminifyfunction whenparalleloption enabled.
webpack.config.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,
}),
],
},
};
terserOptionsType:
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
Terser options.
webpack.config.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,
},
}),
],
},
};
extractCommentsType:
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).
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.
booleanEnable/disable extracting comments.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
extractComments: true,
}),
],
},
};
stringExtract all or some (use the /^\**!|@preserve|@license|@cc_on/i RegExp) comments.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
extractComments: "all",
}),
],
},
};
RegExpAll comments that match the given expression will be extracted to a separate file.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
extractComments: /@extract/i,
}),
],
},
};
functionAll comments that match the given expression will be extracted to a separate file.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
extractComments: (astNode, comment) => {
if (/@extract/i.test(comment.value)) {
return true;
}
return false;
},
}),
],
},
};
objectAllows you to customize condition for extracting comments, and specify the extracted file name and banner.
webpack.config.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 ${licenseFile}`,
},
}),
],
},
};
conditionType:
type condition =
| boolean
| "all"
| "some"
| RegExp
| ((
astNode: any,
comment: {
value: string;
type: "comment1" | "comment2" | "comment3" | "comment4";
pos: number;
line: number;
col: number;
},
) => boolean)
| undefined;
The condition that determines which comments should be extracted.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
extractComments: {
condition: "some",
filename: (fileData) =>
// The "fileData" argument contains object with "filename", "basename", "query" and "hash"
`${fileData.filename}.LICENSE.txt${fileData.query}`,
banner: (licenseFile) =>
`License information can be found in ${licenseFile}`,
},
}),
],
},
};
filenameType:
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
.txtextension. Using.js/.cjs/.mjsextensions may conflict with existing assets, which leads to broken code.
webpack.config.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}`,
},
}),
],
},
};
bannerType:
type banner = string | boolean | ((commentsFile: string) => string) | undefined;
Default: /*! For license information please see ${commentsFile} */
The banner text that points to the extracted file and will be added at the top of the original file.
It can be false (no banner), a String, or a function<(string) -> String> that will be called with the filename where the extracted comments have been stored.
The banner will be wrapped in a comment.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
extractComments: {
condition: true,
filename: (fileData) =>
// The "fileData" argument contains object with "filename", "basename", "query" and "hash"
`${fileData.filename}.LICENSE.txt${fileData.query}`,
banner: (commentsFile) =>
`My custom banner about license information ${commentsFile}`,
},
}),
],
},
};
Extract all legal comments (i.e. /^\**!|@preserve|@license|@cc_on/i) and preserve /@license/i comments.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
terserOptions: {
format: {
comments: /@license/i,
},
},
extractComments: true,
}),
],
},
};
If you want to build without comments, use this config:
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
terserOptions: {
format: {
comments: false,
},
},
extractComments: false,
}),
],
},
};
uglify-jsUglifyJS is a JavaScript parser, minifier, compressor and beautifier toolkit.
webpack.config.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: {},
}),
],
},
};
swcswc is a super-fast compiler written in Rust, producing widely supported JavaScript from modern standards and TypeScript.
Warning
The
extractCommentsoption is not supported, and all comments will be removed by default. This will be fixed in future
webpack.config.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: {},
}),
],
},
};
esbuildesbuild is an extremely fast JavaScript bundler and minifier.
Warning
The
extractCommentsoption is not supported, and all legal comments (i.e. copyright, licenses and etc) will be preserved.
webpack.config.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: {},
}),
],
},
};
Uses JSON.stringify() to minify your JSON files during the build process.
webpack.config.js
module.exports = {
optimization: {
minimize: true,
minimizer: [
// Keeps original terser plugin to minify JS files
"...",
// Will minify JSON files (they can come from copy-webpack-plugin or when you are using asset modules)
new TerserPlugin({
test: /\.json$/,
minify: TerserPlugin.jsonMinify,
// We are supporting `space` and `replacer` options, you can set them below
terserOptions: {},
}),
],
},
};
Override the default minify function - use uglify-js for minification.
webpack.config.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);
},
}),
],
},
};
With default Terser minify function:
module.exports = {
optimization: {
minimize: true,
minimizer: [
new TerserPlugin({
terserOptions: {
compress: true,
},
}),
],
},
};
With built-in minify functions:
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<SwcOptions>({
minify: TerserPlugin.swcMinify,
terserOptions: {
// `swc` options
},
}),
new TerserPlugin<UglifyJSOptions>({
minify: TerserPlugin.uglifyJsMinify,
terserOptions: {
// `uglif-js` options
},
}),
new TerserPlugin<EsbuildOptions>({
minify: TerserPlugin.esbuildMinify,
terserOptions: {
// `esbuild` options
},
}),
// Alternative usage:
new TerserPlugin<TerserOptions>({
minify: TerserPlugin.terserMinify,
terserOptions: {
// `terser` options
},
}),
],
},
};
We welcome all contributions! If you're new here, please take a moment to review our contributing guidelines before submitting issues or pull requests.
This package is similar to terser-webpack-plugin as it also minifies JavaScript files. However, it uses UglifyJS for minification instead of Terser. Terser is a fork of UglifyJS with ES6+ support, so terser-webpack-plugin might be more suitable for projects using modern JavaScript features.
This plugin uses babel-minify for minifying JavaScript. It is similar to terser-webpack-plugin but leverages the Babel toolchain. It might be a better choice for projects that are already using Babel for JavaScript transpilation.
Closure-webpack-plugin uses Google's Closure Compiler for minifying JavaScript, which is known for its advanced optimizations. It can be more aggressive in optimization compared to terser-webpack-plugin, but it may also require more configuration and might not support all modern JavaScript features as well as Terser.
FAQs
Terser plugin for webpack
The npm package terser-webpack-plugin receives a total of 35,068,198 weekly downloads. As such, terser-webpack-plugin popularity was classified as popular.
We found that terser-webpack-plugin demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 6 open source maintainers collaborating on the project.
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