imagemin-webp-webpack-plugin

Webpack plugin which converts images to the WebP format while also keeping the original files. Compatible with webpack 5, webpack 4 and previous versions as well.

It uses imagemin, imagemin-webp and imagemin-gif2webp under the hood.

Motivation

Although WebP images are not currently supported in all browsers, they are at least 25% smaller than PNG's or JPEG's. So, certain users can get a much better experience. WebP also supports Gif-like functionality so this plugin also works for GIF images.

Check the support tables on Can I use

Installation

$ npm install imagemin-webp-webpack-plugin --save-dev

Usage

In order to use this plugin, add it to your webpack config.

const ImageminWebpWebpackPlugin= require("imagemin-webp-webpack-plugin");

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

⚠ Keep in mind that plugin order matters, so usually you'd want to put it last.

API

new ImageminWebpWebpackPlugin( [settings] );

settings

Type: Object

Default:

{
  config: [{
    test: /\.(jpe?g|png)/,
    options: {
      quality:  75
    }
  }],
  overrideExtension: true,
  detailedLogs: false,
  silent: false,
  strict: true
}

config

Type Array<Object: {test, options} >

The main config of the plugin which controls how different file types are converted. Each item in the array is an object with 2 properties:

• test - a RegExp selecting just certain images. Supported image formats are JPG, PNG and GIF.
• options -the converting options for the images that pass the above RegExp

⚠ The options object is actually the same one from the imagemin-webp plugin so check their documentation for the available settings.

overrideExtension

Type: boolean Default: true

By default the plugin will override the original file extension, so you will get: image.png -> image.webp

In case you want to concat '.webp' at the end of the file name, set the config value to false. Ex: image.png -> image.png.webp. It may be useful when using nginx or similar to serve .webp files, if http-accept header contains webp just add a suffix to the requested image.

detailedLogs

Type: boolean Default: false

By default the plugin will print to the console

1. the total number of megabytes saved by the webp images compared to the original ones
2. the number of images that failed being converted

This options tells the plugin to also log the size difference per converted image and the names of the images that failed conversion.

silent

Type: boolean Default: false

In case you don't want anything printed to the console set this option to false. This will override the detailedLogs option.

strict

Type: boolean Default: true

By default the webpack build will fail if any of the images that match your RegExps fail the conversion.

This option tells the plugin to not crash the build and keep going :)

Compatibility & known issues

Recently we updated this plugin to make it compatible with webpack 5. Originally it was built for webpack 4 and earlier versions, so I expect it would be compatible no matter the project :)

However, there is a known issue with css-loader@latest where importing .webp images will fail because they don't exist prior the build time. For example this CSS code:

body {
  backgrund-image: url('/assets/cover.webp')
}

will fail since initially only cover.jpg exists, and cover.webp is created dynamically by this Plugin.

Please read some more about this here and upvote the issue if you want me to implement a fix :D

Other mentions

• it doesn't re-convert images while developing
• if you change the actual image but keep the name, somehow webpack is smart enough to detect this and it will re-convert just that image
• there are 2 projects used to test if/how this plugin works in webpack 5 and webpack 4. The projects are: test-project and test-project-webpack5.