Registry / devops / uglifyjs-webpack-plugin

uglifyjs-webpack-plugin

library2.2.0jsnpmunverified

UglifyJS Webpack Plugin uses UglifyJS (v2) to minify JavaScript bundles generated by webpack. The latest stable version is 2.2.0, released July 2019, supporting webpack 4+ and Node 6.9+. It offers caching, parallelization, source maps, and advanced options like chunk filtering. However, it is now largely superseded by terser-webpack-plugin, which supports ES6+ and is the recommended minimizer for webpack 4+. This plugin switched back from uglify-es to uglify-js in v2.0.0, meaning it does not handle modern JavaScript (ES6+) out of the box. It is in maintenance mode with no active development.

devops

npm install uglifyjs-webpack-plugin

github ↗package ↗

INSTALL

IMPORT

SIG · UGLIFYJS-WEBPACK-P

uglifyjs-webpack-plugin

devopsjavascriptv2.2.0

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

UglifyJsPlugin

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

✗ import UglifyJsPlugin from 'uglifyjs-webpack-plugin';

This package provides a CommonJS default export; ESM import may fail in some bundlers.

UglifyJsPlugin

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

✗ import { UglifyJsPlugin } from 'uglifyjs-webpack-plugin';

Named import is incorrect; the plugin is exported as a single default.

default

✓ import UglifyJsPlugin from 'uglifyjs-webpack-plugin';

If using ESM, use default import, but ensure your environment supports it. CJS require() is safer.

Configures webpack to use UglifyJS plugin with caching, parallelization, source maps, and options to remove console logs and comments.

const UglifyJsPlugin = require('uglifyjs-webpack-plugin'); module.exports = { mode: 'production', optimization: { minimizer: [ new UglifyJsPlugin({ cache: true, parallel: true, sourceMap: true, uglifyOptions: { compress: { drop_console: true, }, output: { comments: false, }, }, }), ], }, };

Debug

Known issues

breakinguglify-es has been abandoned; uglifyjs-webpack-plugin switched back to uglify-js in v2.0.0.

fix

For ES6+ support, migrate to terser-webpack-plugin.

affects: >=2.0.0

deprecatedThis plugin is in maintenance mode; no new features are being added.

fix

Use terser-webpack-plugin for active development and ES6+ minification.

affects: >=2.0.0

gotchaParallelization may fail on Windows Subsystem for Linux (WSL); disable with parallel: false.

fix

Set parallel: false in plugin options.

affects: >=2.1.3

gotchaDefault cache directory is node_modules/.cache/uglifyjs-webpack-plugin; may cause issues in CI environments.

fix

Set cache to a custom path or disable cache in CI.

affects: >=2.0.0

gotchaPlugin options must be placed under webpack optimization.minimizer, not under plugins.

fix

Use optimization: { minimizer: [new UglifyJsPlugin()] } in webpack config.

affects: >=2.0.0

breakingDefault extract comment condition is case insensitive, may produce different results than v1.

fix

Explicitly set extractComments option to control comment extraction.

affects: >=2.0.0

Errors

Common errors & fixes

Error: Plugin could not be used because optimization.minimizer is not an array.

Plugin is placed directly in plugins array instead of optimization.minimizer.

fix

Move the plugin instance to optimization: { minimizer: [new UglifyJsPlugin()] }.

TypeError: Cannot read property 'call' of undefined

Incorrect import or missing 'new' keyword when instantiating plugin.

fix

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

Error: uglify-js@3.x is not compatible with this plugin.

Package depends on uglify-js v2, but uglify-js v3 is installed.

fix

Ensure uglify-js version 2.x is installed (npm install uglify-js@2).

UglifyJsPlugin: parallel option not supported in single-threaded mode

Setting parallel: true on platforms with a single CPU or where worker farm fails.

fix

Set parallel: false or ensure worker-farm is properly installed.

Upgrade

Version history

2.2.0latest on npm

Audit

Dependencies

webpackrequiredWorks as a webpack plugin, requires webpack 4+

Agent activity

9 hits · last 30 days

node

Resources

githubhttps://github.com/webpack-contrib/uglifyjs-webpack-plugin ↗

packagehttps://www.npmjs.com/package/uglifyjs-webpack-plugin ↗