License Webpack Plugin

4.0.2 verified Sat Apr 25 auth: no javascript

A webpack plugin that extracts third-party library license information and outputs it to a file or adds a banner. Current stable version is 4.0.2. It supports webpack 4 and 5, outputs licenses per chunk or aggregated, and allows exclusion/inclusion patterns. Compared to alternatives, it offers comprehensive configuration for license compliance in webpack builds.

Common errors

error TypeError: LicenseWebpackPlugin is not a constructor ↓

cause Using default import/require without destructuring (e.g., `const LicenseWebpackPlugin = require('license-webpack-plugin')`)

fix

Use const { LicenseWebpackPlugin } = require('license-webpack-plugin') or import { LicenseWebpackPlugin } from 'license-webpack-plugin'

error Error: Cannot find module 'license-webpack-plugin' ↓

cause The package is not installed or installed as devDependency incorrectly.

fix

Run npm install --save-dev license-webpack-plugin

error No license information found for some modules ↓

cause Certain packages do not include license information in their package.json.

fix

Use licenseTypeOverrides option to manually specify licenses for such packages.

Warnings

gotcha The plugin does not automatically scan packages imported via SASS @import or other non-JS modules. ↓

fix Manually specify additional modules using the `additionalModules` option.

gotcha Requires webpack 4 or 5; not compatible with webpack 3 or earlier. ↓

fix Upgrade webpack to version 4 or 5, or use an older version of the plugin (e.g., 2.x) for webpack 3.

gotcha Default output adds a banner to all JavaScript assets; may conflict with CSP (Content Security Policy). ↓

fix Set `addBanner: false` in plugin options to suppress banner injection.

breaking Version 4.x changed default export to named export 'LicenseWebpackPlugin'. ↓

fix Update import from default import to named import: `const { LicenseWebpackPlugin } = require('license-webpack-plugin')`

Install

npm install license-webpack-plugin

yarn add license-webpack-plugin

pnpm add license-webpack-plugin

Imports

LicenseWebpackPlugin

wrong

const LicenseWebpackPlugin = require('license-webpack-plugin');

correct

const { LicenseWebpackPlugin } = require('license-webpack-plugin');

CommonJS require must destructure the named export 'LicenseWebpackPlugin'.

LicenseWebpackPlugin

wrong

import LicenseWebpackPlugin from 'license-webpack-plugin';

correct

import { LicenseWebpackPlugin } from 'license-webpack-plugin';

ESM import must use named import. Default export does not exist.

PluginOptions
```
import { PluginOptions } from 'license-webpack-plugin';
```
TypeScript type import for configuration object (only needed when using TypeScript).

Quickstart

Creates a webpack plugin instance that writes a licenses.txt file, marks GPL and AGPL licenses as unacceptable, and customizes the license output format.

const { LicenseWebpackPlugin } = require('license-webpack-plugin');
module.exports = {
  plugins: [
    new LicenseWebpackPlugin({
      outputFilename: 'licenses.txt',
      unacceptableLicenseTest: (licenseType) => licenseType === 'GPL' || licenseType === 'AGPL',
      renderLicenses: (modules) => modules.map(m => `Package: ${m.name} - License: ${m.licenseId}`).join('\n'),
    })
  ]
};