JsonMinimizerPlugin

5.0.1 verified Sat Apr 25 auth: no javascript

A Webpack plugin that minifies JSON assets using JSON.stringify(). Version 5.0.1 (stable). Maintained by the webpack-contrib team with regular updates; breaking changes follow major Node.js and Webpack version bumps. Differentiators: lightweight alternative to heavier minifiers, integrates seamlessly with Webpack's optimization minimizer array, supports include/exclude patterns and custom JSON.stringify options (space/replacer). Ships TypeScript definitions. Requires Node.js >= 18.12.0 and webpack >= 5.1.0.

Common errors

error Error: '...' is not a valid minimizer. Use '...' to extend default minimizers. ↓

cause Forgetting to include the spread operator when adding custom minimizers alongside defaults

fix

Add '...' as an entry in the minimizer array before your custom plugin

error TypeError: Cannot read properties of undefined (reading 'test') ↓

cause Plugin instantiated without `new` keyword or imported incorrectly

fix

Use new JsonMinimizerPlugin({...}) and ensure default import

Warnings

breaking Node.js version < 18.12.0 is not supported ↓

fix Upgrade Node.js to >= 18.12.0

breaking Minimum webpack version changed to 5.1.0 ↓

fix Update webpack to >= 5.1.0

breaking TypeScript type exports changed: removed CJS wrapper and namespace exports ↓

fix Switch to default import for the plugin class; use type imports for options

gotcha Plugin only minifies JSON that passes through Webpack as assets (not import/require of .json files which are inlined) ↓

fix Use type: 'asset/resource' in module rules or copy-plugin to treat JSON as separate files

gotcha The plugin uses JSON.stringify which may produce output that is not strictly valid JSON if replacer is incorrectly typed ↓

fix Ensure replacer is null, a function, or an array of strings/numbers

Install

npm install json-minimizer-webpack-plugin

yarn add json-minimizer-webpack-plugin

pnpm add json-minimizer-webpack-plugin

Imports

JsonMinimizerPlugin

wrong

const JsonMinimizerPlugin = require('json-minimizer-webpack-plugin')

correct

import JsonMinimizerPlugin from 'json-minimizer-webpack-plugin'

Default export; CommonJS require works but TypeScript may prefer import. Plugin is the default export.

JsonMinimizerPlugin (type)

wrong

const { JsonMinimizerPluginOptions } = require('json-minimizer-webpack-plugin')

correct

import type { JsonMinimizerPluginOptions } from 'json-minimizer-webpack-plugin'

Type export available for options. Only for TypeScript projects.

constructor options

wrong

new JsonMinimizerPlugin() // no options

correct

new JsonMinimizerPlugin({ test: /\.json$/i, include: [...], exclude: [...], minimizerOptions: { space: 0 } })

All options optional; default test matches any .json file.

Quickstart

Shows the minimal configuration: install plugin, add to optimization.minimizer, and copy JSON files with minification.

const path = require('path');
const CopyPlugin = require('copy-webpack-plugin');
const JsonMinimizerPlugin = require('json-minimizer-webpack-plugin');

module.exports = {
  mode: 'production',
  entry: './src/index.js',
  output: { path: path.resolve(__dirname, 'dist') },
  module: {
    rules: [
      { test: /\.json$/i, type: 'asset/resource' }
    ]
  },
  plugins: [
    new CopyPlugin({
      patterns: [{ from: './src/*.json', to: '[name][ext]' }]
    })
  ],
  optimization: {
    minimize: true,
    minimizer: [
      `...`,
      new JsonMinimizerPlugin({
        test: /\.json$/i,
        minimizerOptions: { space: 0 }
      })
    ]
  }
};