webpack-parallel-uglify-plugin

2.0.0 verified Sat Apr 25 auth: no javascript maintenance

A webpack plugin that runs UglifyJS (or Terser) in parallel across multiple workers to speed up minification of bundled assets. Version 2.0.0 is the current stable release, but the project appears to be in maintenance mode with no recent updates (last release 2019). It leverages Node.js worker threads to distribute minification of each output file across available CPU cores, offering significant build time reductions for projects with many entry points. Compared to built-in webpack UglifyJS plugin, it can reduce minification time from minutes to seconds. Supports both UglifyJS (ES5) and Terser (ES6+), along with caching, file inclusion/exclusion by pattern, and source maps. Requires webpack as a peer dependency.

Common errors

error Error: Cannot find module 'webpack-parallel-uglify-plugin' ↓

cause Package not installed or import path incorrect.

fix

Run 'npm install webpack-parallel-uglify-plugin --save-dev' and ensure correct import statement.

error TypeError: ParallelUglifyPlugin is not a constructor ↓

cause Using CommonJS require without accessing .default property.

fix

Use 'const ParallelUglifyPlugin = require('webpack-parallel-uglify-plugin').default;'

error Error: ParallelUglifyPlugin: you cannot use both uglifyJS and terser ↓

cause Both minifier options provided simultaneously.

fix

Remove one of the options: either uglifyJS or terser.

Warnings

deprecated The package is outdated and unmaintained; consider using 'terser-webpack-plugin' which is officially maintained by the webpack team. ↓

fix Replace with 'terser-webpack-plugin' and update configuration accordingly.

breaking Cannot use both 'uglifyJS' and 'terser' options simultaneously. If both are provided, the plugin will throw an error. ↓

fix Choose only one minifier: either UglifyJS or Terser.

gotcha With UglifyJS (not Terser), ES6+ syntax will cause an error because UglifyJS only supports ES5. Use terser option for ES6+. ↓

fix Set terser options instead of uglifyJS if your code uses ES6+.

Install

npm install webpack-parallel-uglify-plugin

yarn add webpack-parallel-uglify-plugin

pnpm add webpack-parallel-uglify-plugin

Imports

default

wrong

const ParallelUglifyPlugin = require('webpack-parallel-uglify-plugin')

correct

import ParallelUglifyPlugin from 'webpack-parallel-uglify-plugin'

ESM default import is correct; CommonJS require works but may have issues with default export

ParallelUglifyPlugin

wrong

const ParallelUglifyPlugin = require('webpack-parallel-uglify-plugin')

correct

const ParallelUglifyPlugin = require('webpack-parallel-uglify-plugin').default

If using CommonJS, the default export is under .default property

ParallelUglifyPlugin

wrong

import { ParallelUglifyPlugin } from 'webpack-parallel-uglify-plugin'

correct

import { default as ParallelUglifyPlugin } from 'webpack-parallel-uglify-plugin'

Named import does not exist; only default export

Quickstart

Shows how to configure the plugin with UglifyJS options, caching, and worker count.

// webpack.config.js
import ParallelUglifyPlugin from 'webpack-parallel-uglify-plugin';

export default {
  entry: './src/index.js',
  output: {
    filename: 'bundle.js',
    path: '/dist',
  },
  plugins: [
    new ParallelUglifyPlugin({
      workerCount: 4,
      uglifyJS: {
        output: {
          beautify: false,
        },
        compress: {
          drop_console: true,
        },
      },
      cacheDir: '/path/to/cache',
      sourceMap: false,
      include: /\.js$/,
      exclude: /node_modules/,
      test: /\.js$/,
    }),
  ],
};