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[![node][node]][node-url]
[![deps][deps]][deps-url]
[![tests][tests]][tests-url]
[![cover][cover]][cover-url]
[![chat][chat]][chat-url]
[![size][size]][size-url]

compression-webpack-plugin

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

Getting Started

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

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

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

webpack.config.js

`js
const CompressionPlugin = require("compression-webpack-plugin");

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

And run webpack via your preferred method.

Options

| Name | Type | Default | Description |
| :-------------------------------------------------: | :---------------------------------------: | :-----------------------------------------------------------: | :------------------------------------------------------------------------------------------------------------ |
| test | {String\|RegExp\|Array} | undefined | Include all assets that pass test assertion |
| include | {String\|RegExp\|Array} | undefined | Include all assets matching any of these conditions |
| exclude | {String\|RegExp\|Array} | undefined | Exclude all assets matching any of these conditions |
| algorithm | {String\|Function} | gzip | The compression algorithm/function |
| compressionOptions | {Object} | maximum available compression level, for gzip: { level: 9 } | Compression options for algorithm |
| threshold | {Number} | 0 | Only assets bigger than this size are processed (in bytes) |
| minRatio | {Number} | 0.8 | Only assets that compress better than this ratio are processed (minRatio = Compressed Size / Original Size) |
| filename | {String\|Function} | [path][base].gz | The target asset filename |
| deleteOriginalAssets | {Boolean\|'keep-source-map'} | false | Whether to delete the original assets or not |
| cache | {Boolean} | true | Enable file caching |

$3

Type: String|RegExp|Array
Default: undefined

Include all assets that pass test assertion.

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
test: /\.js(\?.*)?$/i,
}),
],
};
`

$3

Type: String|RegExp|Array
Default: undefined

Include all assets matching any of these conditions.

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
include: /\/includes/,
}),
],
};
`

$3

Type: String|RegExp|Array
Default: undefined

Exclude all assets matching any of these conditions.

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
exclude: /\/excludes/,
}),
],
};
`

$3

Type: String|Function
Default: gzip

The compression algorithm/function.

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

#### String

The algorithm is taken from zlib.

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
algorithm: "gzip",
}),
],
};
`

#### Function

Allow to specify a custom compression function.

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
algorithm(input, compressionOptions, callback) {
return compressionFunction(input, compressionOptions, callback);
},
}),
],
};
`

$3

Type: Object
Default: { level: 9 }

Compression options for algorithm.

You can find all options here zlib.

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

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
compressionOptions: { level: 1 },
}),
],
};
`

$3

Type: Number
Default: 0

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

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
threshold: 8192,
}),
],
};
`

$3

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 Infinity to process all assets even if they are larger than the original size or their original size is 0 bytes (useful when you are pre-zipping all assets for AWS).

Use a value of Number.MAX_SAFE_INTEGER to process all assets even if they are larger than the original size, excluding assets with their original size is 0 bytes.

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
// Compress all assets, including files with 0 bytes size
// minRatio: Infinity

// Compress all assets, excluding files with 0 bytes size
// minRatio: Number.MAX_SAFE_INTEGER

minRatio: 0.8,
}),
],
};
`

$3

Type: String|Function
Default: "[path][base].gz"

The target asset filename.

#### String

For example we have assets/images/image.png?foo=bar#hash:

[path] is replaced with the directories to the original asset, included trailing / (assets/images/).

[file] is replaced with the path of original asset (assets/images/image.png).

[base] is replaced with the base ([name] + [ext]) of the original asset (image.png).

[name] is replaced with the name of the original asset (image).

[ext] is replaced with the extension of the original asset, included . (.png).

[query] is replaced with the query of the original asset, included ? (?foo=bar).

[fragment] is replaced with the fragment (in the concept of URL it is called hash) of the original asset (#hash).

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
filename: "[path][base].gz",
}),
],
};
`

#### Function

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
filename(pathData) {
// The pathData argument contains all placeholders - path/name/ext/etc
// Available properties described above, for the String notation
if (/\.svg$/.test(pathData.file)) {
return "assets/svg/[path][base].gz";
}

return "assets/js/[path][base].gz";
},
}),
],
};
`

$3

Type: Boolean | 'keep-source-map'
Default: false

Whether to delete the original assets or not.

webpack.config.js

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

To exclude sourcemaps from compression

`js
module.exports = {
plugins: [
new CompressionPlugin({
exclude: /.map$/
deleteOriginalAssets: 'keep-source-map',
}),
],
};
`

$3

> ⚠ Ignored in webpack 5! Please use https://webpack.js.org/configuration/other-options/#cache.

Type: Boolean|String
Default: true

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

#### Boolean

Enable/disable file caching.

webpack.config.js

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

#### String

Enable file caching and set path to cache directory.

webpack.config.js

`js
module.exports = {
plugins: [
new CompressionPlugin({
cache: "path/to/cache",
}),
],
};
`

Examples

$3

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:

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

webpack.config.js

`js
const zopfli = require("@gfx/zopfli");

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

$3

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

Node 10.16.0 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 10.16.0 and later by just passing in the appropriate algorithm to the CompressionPlugin:

webpack.config.js

`js
const zlib = require("zlib");

module.exports = {
plugins: [
new CompressionPlugin({
filename: "[path][base].br",
algorithm: "brotliCompress",
test: /\.(js|css|html|svg)$/,
compressionOptions: {
params: {
[zlib.constants.BROTLI_PARAM_QUALITY]: 11,
},
},
threshold: 10240,
minRatio: 0.8,
deleteOriginalAssets: false,
}),
],
};
`

Note Brotli’s BROTLI_PARAM_QUALITY option is functionally equivalent to zlib’s level option.
You can find all Brotli’s options in the relevant part of the zlib module documentation.

$3

webpack.config.js

`js
const zlib = require("zlib");

module.exports = {
plugins: [
new CompressionPlugin({
filename: "[path][base].gz",
algorithm: "gzip",
test: /\.js$|\.css$|\.html$/,
threshold: 10240,
minRatio: 0.8,
}),
new CompressionPlugin({
filename: "[path][base].br",
algorithm: "brotliCompress",
test: /\.(js|css|html|svg)$/,
compressionOptions: {
params: {
[zlib.constants.BROTLI_PARAM_QUALITY]: 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

[npm]: https://img.shields.io/npm/v/compression-webpack-plugin.svg
[npm-url]: https://npmjs.com/package/compression-webpack-plugin
[node]: https://img.shields.io/node/v/compression-webpack-plugin.svg
[node-url]: https://nodejs.org
[deps]: https://david-dm.org/webpack-contrib/compression-webpack-plugin.svg
[deps-url]: https://david-dm.org/webpack-contrib/compression-webpack-plugin
[tests]: https://github.com/webpack-contrib/compression-webpack-plugin/workflows/compression-webpack-plugin/badge.svg
[tests-url]: https://github.com/webpack-contrib/compression-webpack-plugin/actions
[cover]: https://codecov.io/gh/webpack-contrib/compression-webpack-plugin/branch/master/graph/badge.svg
[cover-url]: https://codecov.io/gh/webpack-contrib/compression-webpack-plugin
[chat]: https://img.shields.io/badge/gitter-webpack%2Fwebpack-brightgreen.svg
[chat-url]: https://gitter.im/webpack/webpack
[size]: https://packagephobia.now.sh/badge?p=compression-webpack-plugin
[size-url]: https://packagephobia.now.sh/result?p=compression-webpack-plugin