uglifyjs-webpack-plugin

What is uglifyjs-webpack-plugin?

The uglifyjs-webpack-plugin is a plugin for Webpack that uses UglifyJS to minify JavaScript files. It helps in reducing the size of JavaScript files by removing unnecessary characters, comments, and whitespace, and by optimizing the code.

What are uglifyjs-webpack-plugin's main functionalities?

Basic Minification

This feature allows you to perform basic minification of JavaScript files using UglifyJS. The code sample demonstrates how to configure the plugin in a Webpack configuration file to minimize the output JavaScript files.

const UglifyJsPlugin = require('uglifyjs-webpack-plugin');

module.exports = {
  optimization: {
    minimizer: [new UglifyJsPlugin()]
  }
};

Custom UglifyJS Options

This feature allows you to customize the UglifyJS options. The code sample shows how to configure the plugin to remove console statements from the output JavaScript files.

const UglifyJsPlugin = require('uglifyjs-webpack-plugin');

module.exports = {
  optimization: {
    minimizer: [
      new UglifyJsPlugin({
        uglifyOptions: {
          compress: {
            drop_console: true,
          },
        },
      }),
    ],
  },
};

Source Map Support

This feature enables source map support, which helps in debugging minified code. The code sample demonstrates how to configure the plugin to generate source maps for the minified JavaScript files.

const UglifyJsPlugin = require('uglifyjs-webpack-plugin');

module.exports = {
  devtool: 'source-map',
  optimization: {
    minimizer: [
      new UglifyJsPlugin({
        sourceMap: true,
      }),
    ],
  },
};

Other packages similar to uglifyjs-webpack-plugin

terser-webpack-plugin

The terser-webpack-plugin is a Webpack plugin that uses Terser to minify JavaScript files. Terser is a fork of UglifyJS with better support for ES6+ syntax. It is often preferred over uglifyjs-webpack-plugin for modern JavaScript projects due to its better handling of newer JavaScript features.

babel-minify-webpack-plugin

The babel-minify-webpack-plugin is a Webpack plugin that uses Babel Minify (babel-minify) to minify JavaScript files. It is designed to work seamlessly with Babel and offers a wide range of minification options. It is a good alternative to uglifyjs-webpack-plugin, especially if you are already using Babel in your project.

closure-webpack-plugin

The closure-webpack-plugin is a Webpack plugin that uses Google Closure Compiler to minify JavaScript files. It offers advanced optimizations and is capable of performing aggressive code transformations. It is suitable for large projects that require high levels of optimization and code analysis.

README

UglifyJS Webpack Plugin

This plugin uses UglifyJS v3 (`uglify-es`) to minify your JavaScript

ℹ️ webpack =< v3.0.0 currently contains v0.4.6 of this plugin under webpack.optimize.UglifyJsPlugin as an alias. For usage of the latest version (v1.0.0), please follow the instructions below. Aliasing v1.0.0 as webpack.optimize.UglifyJsPlugin is scheduled for webpack v4.0.0

Install

npm i -D uglifyjs-webpack-plugin

Usage

webpack.config.js

const UglifyJsPlugin = require('uglifyjs-webpack-plugin')

module.exports = {
  plugins: [
    new UglifyJsPlugin()
  ]
}

Options

Name	Type	Default	Description
test	{RegExp|Array<RegExp>}	/\.js$/i	Test to match files against
include	{RegExp|Array<RegExp>}	undefined	Files to include
exclude	{RegExp|Array<RegExp>}	undefined	Files to exclude
cache	{Boolean|String}	false	Enable file caching
parallel	{Boolean|Number}	false	Use multi-process parallel running to improve the build speed
sourceMap	{Boolean}	false	Use source maps to map error message locations to modules (This slows down the compilation) ⚠️ cheap-source-map options don't work with this plugin
uglifyOptions	{Object}	{...defaults}	uglify Options
extractComments	{Boolean|RegExp|Function<(node, comment) -> {Boolean|Object}>}	false	Whether comments shall be extracted to a separate file, (see details (webpack >= 2.3.0)
warningsFilter	{Function(source) -> {Boolean}}	() => true	Allow to filter uglify warnings

test

webpack.config.js

[
  new UglifyJsPlugin({
    test: /\.js($|\?)/i
  })
]

include

webpack.config.js

[
  new UglifyJsPlugin({
    include: /\/includes/
  })
]

exclude

webpack.config.js

[
  new UglifyJsPlugin({
    exclude: /\/excludes/
  })
]

cache

{Boolean}

webpack.config.js

[
  new UglifyJsPlugin({
    cache: true
  })
]

Enable file caching. Default path to cache directory: node_modules/.cache/uglifyjs-webpack-plugin.

{String}

webpack.config.js

[
  new UglifyJsPlugin({
    cache: 'path/to/cache'
  })
]

Path to cache directory.

parallel

{Boolean}

webpack.config.js

[
  new UglifyJsPlugin({
    parallel: true
  })
]

Enable parallelization. Default number of concurrent runs: os.cpus().length - 1.

{Number}

webpack.config.js

[
  new UglifyJsPlugin({
    parallel: 4
  })
]

Number of concurrent runs.

ℹ️ Parallelization can speedup your build significantly and is therefore highly recommended

sourceMap

webpack.config.js

[
  new UglifyJsPlugin({
    sourceMap: true
  })
]

⚠️ cheap-source-map options don't work with this plugin

uglifyOptions

Name	Type	Default	Description
ecma	{Number}	undefined	Supported ECMAScript Version (5, 6, 7 or 8). Affects parse, compress && output options
warnings	{Boolean}	false	Display Warnings
parse	{Object}	{}	Additional Parse Options
compress	{Boolean|Object}	true	Additional Compress Options
mangle	{Boolean|Object}	true	Enable Name Mangling (See Mangle Properties for advanced setups, use with ⚠️)
output	{Object}	{}	Additional Output Options (The defaults are optimized for best compression)
toplevel	{Boolean}	false	Enable top level variable and function name mangling and to drop unused variables and functions
nameCache	{Object}	null	Enable cache of mangled variable and property names across multiple invocations
ie8	{Boolean}	false	Enable IE8 Support
keep_classnames	{Boolean}	undefined	Enable prevent discarding or mangling of class names
keep_fnames	{Boolean}	false	Enable prevent discarding or mangling of function names. Useful for code relying on Function.prototype.name. If the top level minify option keep_classnames is undefined it will be overriden with the value of the top level minify option keep_fnames
safari10	{Boolean}	false	Enable work around Safari 10/11 bugs in loop scoping and await

webpack.config.js

[
  new UglifyJsPlugin({
    uglifyOptions: {
      ecma: 8,
      warnings: false,
      parse: {...options},
      compress: {...options},
      mangle: {
        ...options,
        properties: {
          // mangle property options
        }
      },
      output: {
        comments: false,
        beautify: false,
        ...options
      },
      toplevel: false,
      nameCache: null,
      ie8: false,
      keep_classnames: undefined,
      keep_fnames: false,
      safari10: false,
    }
  })
]

extractComments

{Boolean}

All comments that normally would be preserved by the comments option will be moved to a separate file. If the original file is named foo.js, then the comments will be stored to foo.js.LICENSE.

{RegExp|String} or {Function<(node, comment) -> {Boolean}>}

All comments that match the given expression (resp. are evaluated to true by the function) will be extracted to the separate file. The 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.

{Object}

Name	Type	Default	Description
condition	{Regex|Function}	``	Regular Expression or function (see previous point)
filename	{String|Function}	${file}.LICENSE	The file where the extracted comments will be stored. Can be either a {String} or a {Function<(string) -> {String}>}, which will be given the original filename. Default is to append the suffix .LICENSE to the original filename
banner	{Boolean|String|Function}	/*! For license information please see ${filename}.js.LICENSE */	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

warningsFilter

webpack.config.js

[
  new UglifyJsPlugin({
    warningsFilter: (src) => true
  })
]

Maintainers

Steven Hargrove

Juho Vepsäläinen

Joshua Wiens

Michael Ciniawsky

Alexander Krasnoyarov

Changelog

1.2.1 (2018-02-23)

Bug Fixes

• index: tapable deprecation warnings (webpack >= v4.0.0) (#238) (23b1b38)

<a name="1.2.0"></a>