CompressionWebpackPlugin

Prepare compressed versions of assets to serve them with Content-Encoding.

Getting Started

To begin, you'll need to install compression-webpack-plugin:

$ npm install compression-webpack-plugin --save-dev

Then add the plugin to your webpack config. For example:

webpack.config.js

const CompressionPlugin = require('compression-webpack-plugin');

module.exports = {
  plugins: [new CompressionPlugin()],
};

And run webpack via your preferred method.

Options

test

Type: String|RegExp|Array<String|RegExp> Default: undefined

Test to match files against.

// in your webpack.config.js
new CompressionPlugin({
  test: /\.js(\?.*)?$/i,
});

include

Type: String|RegExp|Array<String|RegExp> Default: undefined

Files to include.

// in your webpack.config.js
new CompressionPlugin({
  include: /\/includes/,
});

exclude

Type: String|RegExp|Array<String|RegExp> Default: undefined

Files to exclude.

// in your webpack.config.js
new CompressionPlugin({
  exclude: /\/excludes/,
});

cache

Type: Boolean|String Default: false

Enable file caching. The default path to cache directory: node_modules/.cache/compression-webpack-plugin.

Boolean

Enable/disable file caching.

// in your webpack.config.js
new CompressionPlugin({
  cache: true,
});

String

Enable file caching and set path to cache directory.

// in your webpack.config.js
new CompressionPlugin({
  cache: 'path/to/cache',
});

filename

Type: String|Function Default: [path].gz[query]

The target asset filename.

String

[file] is replaced with the original asset filename. [path] is replaced with the path of the original asset. [dir] is replaced with the directory of the original asset. [name] is replaced with the filename of the original asset. [ext] is replaced with the extension of the original asset. [query] is replaced with the query.

// in your webpack.config.js
new CompressionPlugin({
  filename: '[path].gz[query]',
});

new CompressionPlugin({
  filename: '[dir][name].gz[ext][query]',
});

Function

// in your webpack.config.js
new CompressionPlugin({
  filename(info) {
    // info.file is the original asset filename
    // info.path is the path of the original asset
    // info.query is the query
    return `${info.path}.gz${info.query}`;
  },
});

algorithm

Type: String|Function Default: gzip

The compression algorithm/function.

String

The algorithm is taken from zlib.

// in your webpack.config.js
new CompressionPlugin({
  algorithm: 'gzip',
});

Function

Allow to specify a custom compression function.

// in your webpack.config.js
new CompressionPlugin({
  algorithm(input, compressionOptions, callback) {
    return compressionFunction(input, compressionOptions, callback);
  },
});

compressionOptions

Type: Object Default: { level: 9 }

If you use custom function for the algorithm option, the default value is {}.

Compression options. You can find all options here zlib.

// in your webpack.config.js
new CompressionPlugin({
  compressionOptions: { level: 1 },
});

threshold

Type: Number Default: 0

Only assets bigger than this size are processed. In bytes.

// in your webpack.config.js
new CompressionPlugin({
  threshold: 8192,
});

minRatio

Type: Number Default: 0.8

Only assets that compress better than this ratio are processed (minRatio = Compressed Size / Original Size). Example: you have image.png file with 1024b size, compressed version of file has 768b size, so minRatio equal 0.75. In other words assets will be processed when the Compressed Size / Original Size value less minRatio value. You can use 1 value to process assets that are smaller than the original. Use a value of Number.MAX_SAFE_INTEGER to process all assets even if they are larger than the original (useful when you are pre-zipping all assets for AWS)

// in your webpack.config.js
new CompressionPlugin({
  minRatio: 0.8,
});

deleteOriginalAssets

Type: Boolean Default: false

Whether to delete the original assets or not.

// in your webpack.config.js
new CompressionPlugin({
  deleteOriginalAssets: true,
});

Examples

Using Zopfli

Prepare compressed versions of assets using zopfli library.

ℹ️ @gfx/zopfli require minimum 8 version of node.

To begin, you'll need to install @gfx/zopfli:

$ npm install @gfx/zopfli --save-dev

webpack.config.js

const zopfli = require('@gfx/zopfli');

module.exports = {
  plugins: [
    new CompressionPlugin({
      compressionOptions: {
        numiterations: 15,
      },
      algorithm(input, compressionOptions, callback) {
        return zopfli.gzip(input, compressionOptions, callback);
      },
    }),
  ],
};

Using Brotli

Brotli is a compression algorithm originally developed by Google, and offers compression superior to gzip.

Node 11.7.0 and later has native support for Brotli compression in its zlib module.

We can take advantage of this built-in support for Brotli in Node 11.7.0 and later by just passing in the appropriate algorithm to the CompressionPlugin:

webpack.config.js

module.exports = {
  plugins: [
    new CompressionPlugin({
      filename: '[path].br[query]',
      algorithm: 'brotliCompress',
      test: /\.(js|css|html|svg)$/,
      compressionOptions: { level: 11 },
      threshold: 10240,
      minRatio: 0.8,
      deleteOriginalAssets: false,
    }),
  ],
};

N.B.: The level option matches BROTLI_PARAM_QUALITY for Brotli-based streams

Multiple compressed versions of assets for different algorithm

webpack.config.js

module.exports = {
  plugins: [
    new CompressionPlugin({
      filename: '[path].gz[query]',
      algorithm: 'gzip',
      test: /\.js$|\.css$|\.html$/,
      threshold: 10240,
      minRatio: 0.8,
    }),
    new CompressionPlugin({
      filename: '[path].br[query]',
      algorithm: 'brotliCompress',
      test: /\.(js|css|html|svg)$/,
      compressionOptions: { level: 11 },
      threshold: 10240,
      minRatio: 0.8,
    }),
  ],
};

Contributing

Please take a moment to read our contributing guidelines if you haven't yet done so.

CONTRIBUTING

License

MIT