terser-webpack-plugin
This plugin uses terser to minify your JavaScript.
ℹ️ For
webpack@3use terser-webpack-plugin-legacy package
Getting Started
To begin, you'll need to install terser-webpack-plugin:
$ npm install terser-webpack-plugin --save-dev
Then add the plugin to your webpack config. For example:
webpack.config.js
const TerserPlugin = require('terser-webpack-plugin');
module.exports = {
optimization: {
minimizer: [new TerserPlugin()],
},
};
And run webpack via your preferred method.
Options
test
Type: String|RegExp|Array<String|RegExp>
Default: /\.m?js(\?.*)?$/i
Test to match files against.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
test: /\.js(\?.*)?$/i,
}),
],
},
};
include
Type: String|RegExp|Array<String|RegExp>
Default: undefined
Files to include.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
include: /\/includes/,
}),
],
},
};
exclude
Type: String|RegExp|Array<String|RegExp>
Default: undefined
Files to exclude.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
exclude: /\/excludes/,
}),
],
},
};
chunkFilter
Type: Function<(chunk) -> boolean>
Default: () => true
Allowing to filter which chunks should be uglified (by default all chunks are uglified).
Return true to uglify the chunk, false otherwise.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
chunkFilter: (chunk) => {
// Exclude uglification for the `vendor` chunk
if (chunk.name === 'vendor') {
return false;
}
return true;
},
}),
],
},
};
cache
Type: Boolean|String
Default: false
Enable file caching.
Default path to cache directory: node_modules/.cache/terser-webpack-plugin.
ℹ️ If you use your own
minifyfunction please read theminifysection for cache invalidation correctly.
Boolean
Enable/disable file caching.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
cache: true,
}),
],
},
};
String
Enable file caching and set path to cache directory.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
cache: 'path/to/cache',
}),
],
},
};
cacheKeys
Type: Function<(defaultCacheKeys, file) -> Object>
Default: defaultCacheKeys => defaultCacheKeys
Allows you to override default cache keys.
Default cache keys:
({
terser: require('terser/package.json').version, // terser version
'terser-webpack-plugin': require('../package.json').version, // plugin version
'terser-webpack-plugin-options': this.options, // plugin options
path: compiler.outputPath ? `${compiler.outputPath}/${file}` : file, // asset path
hash: crypto
.createHash('md4')
.update(input)
.digest('hex'), // source file hash
});
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
cache: true,
cacheKeys: (defaultCacheKeys, file) => {
defaultCacheKeys.myCacheKey = 'myCacheKeyValue';
return defaultCacheKeys;
},
}),
],
},
};
parallel
Type: Boolean|Number
Default: false
Use multi-process parallel running to improve the build speed.
Default number of concurrent runs: os.cpus().length - 1.
ℹ️ Parallelization can speedup your build significantly and is therefore highly recommended.
Boolean
Enable/disable multi-process parallel running.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
parallel: true,
}),
],
},
};
Number
Enable multi-process parallel running and set number of concurrent runs.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
parallel: 4,
}),
],
},
};
sourceMap
Type: Boolean
Default: false
Use source maps to map error message locations to modules (this slows down the compilation).
If you use your own minify function please read the minify section for handling source maps correctly.
⚠️
cheap-source-mapoptions don't work with this plugin.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
sourceMap: true,
}),
],
},
};
minify
Type: Function
Default: undefined
Allows you to override default minify function. By default plugin uses terser package. Useful for using and testing unpublished versions or forks.
⚠️ Always use
requireinsideminifyfunction whenparalleloption enabled.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
minify: (file, sourceMap) => {
const extractedComments = [];
// Custom logic for extract comments
const { error, map, code, warnings } = require('uglify-module') // Or require('./path/to/uglify-module')
.minify(file, {
/* Your options for minification */
});
return { error, map, code, warnings, extractedComments };
},
}),
],
},
};
terserOptions
Type: Object
Default: default
Terser minify options.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
terserOptions: {
ecma: undefined,
warnings: false,
parse: {},
compress: {},
mangle: true, // Note `mangle.properties` is `false` by default.
module: false,
output: null,
toplevel: false,
nameCache: null,
ie8: false,
keep_classnames: undefined,
keep_fnames: false,
safari10: false,
},
}),
],
},
};
extractComments
Type: Boolean|String|RegExp|Function<(node, comment) -> Boolean|Object>|Object
Default: false
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.
The terserOptions.output.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 preserving comments that have been extracted.
Boolean
Enable/disable extracting comments.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
extractComments: true,
}),
],
},
};
String
Extract all or some (use /^\**!|@preserve|@license|@cc_on/i RegExp) comments.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
extractComments: 'all',
}),
],
},
};
RegExp
All comments that match the given expression will be extracted to the separate file.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
extractComments: /@extract/i,
}),
],
},
};
Function<(node, comment) -> Boolean>
All comments that match the given expression will be extracted to the separate file.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
extractComments: (astNode, comment) => {
if (/@extract/i.test(comment.value)) {
return true;
}
return false;
},
}),
],
},
};
Object
Allow to customize condition for extract comments, specify extracted file name and banner.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
extractComments: {
condition: /^\**!|@preserve|@license|@cc_on/i,
filename: (file) => {
return `${file}.LICENSE`;
},
banner: (licenseFile) => {
return `License information can be found in ${licenseFile}`;
},
},
}),
],
},
};
condition
Type: Boolean|String|RegExp|Function<(node, comment) -> Boolean|Object>
Condition what comments you need extract.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
extractComments: {
condition: 'some',
filename: (file) => {
return `${file}.LICENSE`;
},
banner: (licenseFile) => {
return `License information can be found in ${licenseFile}`;
},
},
}),
],
},
};
filename
Type: String|Function<(string) -> String>
Default: ${file}.LICENSE
The file where the extracted comments will be stored.
Default is to append the suffix .LICENSE to the original filename.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
extractComments: {
condition: /^\**!|@preserve|@license|@cc_on/i,
filename: 'extracted-comments.js',
banner: (licenseFile) => {
return `License information can be found in ${licenseFile}`;
},
},
}),
],
},
};
banner
Type: Boolean|String|Function<(string) -> String>
Default: /*! For license information please see ${commentsFile} */
The banner text that points to the extracted file and will be added on top of the original file.
Can be false (no banner), a String, or a Function<(string) -> String> that will be called with the filename where extracted comments have been stored.
Will be wrapped into comment.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
extractComments: {
condition: true,
filename: (file) => {
return `${file}.LICENSE`;
},
banner: (commentsFile) => {
return `My custom banner about license information ${commentsFile}`;
},
},
}),
],
},
};
warningsFilter
Type: Function<(warning, source) -> Boolean>
Default: () => true
Allow to filter terser warnings.
Return true to keep the warning, false otherwise.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
warningsFilter: (warning, source) => {
if (/Dropping unreachable code/i.test(warning)) {
return true;
}
if (/filename\.js/i.test(source)) {
return true;
}
return false;
},
}),
],
},
};
Examples
Cache And Parallel
Enable cache and multi-process parallel running.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
cache: true,
parallel: true,
}),
],
},
};
Preserve Comments
Extract all legal comments (i.e. /^\**!|@preserve|@license|@cc_on/i) and preserve /@license/i comments.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
terserOptions: {
output: {
comments: /@license/i,
},
},
extractComments: true,
}),
],
},
};
Remove Comments
If you avoid building with comments, set terserOptions.output.comments to false as in this config:
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
terserOptions: {
output: {
comments: false,
},
},
}),
],
},
};
Custom Minify Function
Override default minify function - use uglify-js for minification.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new TerserPlugin({
// Uncomment lines below for cache invalidation correctly
// cache: true,
// cacheKeys: (defaultCacheKeys) => {
// delete defaultCacheKeys.terser;
//
// return Object.assign(
// {},
// defaultCacheKeys,
// { 'uglify-js': require('uglify-js/package.json').version },
// );
// },
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);
},
}),
],
},
};
Contributing
Please take a moment to read our contributing guidelines if you haven't yet done so.