image-minimizer-webpack-plugin

Webpack loader and plugin to optimize (compress) images using imagemin

Usage no npm install needed!

<script type="module">
  import imageMinimizerWebpackPlugin from 'https://cdn.skypack.dev/image-minimizer-webpack-plugin';
</script>

README

Imagemin Webpack

Plugin and Loader for webpack to optimize (compress) all images using imagemin. Do not worry about size of images, now they are always optimized/compressed.

npm node deps tests cover chat size

image-minimizer-webpack-plugin

Getting Started

This plugin can use 2 tools to optimize/generate images:

  • imagemin - optimize your images by default, since it is stable and works with all types of images
  • squoosh - while working in experimental mode with .jpg, .jpeg, .png, .webp, .avif file types.

⚠️ By default we don't install anything

To begin, you'll need to install image-minimizer-webpack-plugin and image minimizer/generator:

$ npm install image-minimizer-webpack-plugin imagemin --save-dev

⚠️ imagemin uses plugin to optimize/generate images, so you need to isntall them too

$ npm install image-minimizer-webpack-plugin @squoosh/lib --save-dev

Images can be optimized in two modes:

  1. Lossless (without loss of quality).
  2. Lossy (with loss of quality).

Optimize with imagemin

Note:

Explore the options to get the best result for you.

Recommended imagemin plugins for lossless optimization

npm install imagemin-gifsicle imagemin-jpegtran imagemin-optipng imagemin-svgo --save-dev

Recommended imagemin plugins for lossy optimization

npm install imagemin-gifsicle imagemin-mozjpeg imagemin-pngquant imagemin-svgo --save-dev

For imagemin-svgo v9.0.0+ need use svgo configuration

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");
const { extendDefaultPlugins } = require("svgo");

module.exports = {
  module: {
    rules: [
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        type: "asset",
      },
    ],
  },
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            // Lossless optimization with custom option
            // Feel free to experiment with options for better result for you
            plugins: [
              ["gifsicle", { interlaced: true }],
              ["jpegtran", { progressive: true }],
              ["optipng", { optimizationLevel: 5 }],
              // Svgo configuration here https://github.com/svg/svgo#configuration
              [
                "svgo",
                {
                  plugins: extendDefaultPlugins([
                    {
                      name: "removeViewBox",
                      active: false,
                    },
                    {
                      name: "addAttributesToSVGElement",
                      params: {
                        attributes: [{ xmlns: "http://www.w3.org/2000/svg" }],
                      },
                    },
                  ]),
                },
              ],
            ],
          },
        },
      }),
    ],
  },
};

Optimize with squoosh

$ npm install @squoosh/lib --save-dev

Recommended @squoosh/lib options for lossy optimization

For lossy optimization we recommend using the default settings of @squoosh/lib package. The default values and supported file types for each option can be found in the codecs.ts file under codecs.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  module: {
    rules: [
      // You need this, if you are using `import file from "file.ext"`, for `new URL(...)` syntax you don't need it
      {
        test: /\.(jpe?g|png)$/i,
        type: "asset",
      },
    ],
  },
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.squooshMinify,
          options: {
            // Your options for `squoosh`
          },
        },
      }),
    ],
  },
};

Recommended squoosh options for lossless optimization

For lossless optimization we recommend using the options listed below in minimizer.options.encodeOptions.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  module: {
    rules: [
      // You need this, if you are using `import file from "file.ext"`, for `new URL(...)` syntax you don't need it
      {
        test: /\.(jpe?g|png)$/i,
        type: "asset",
      },
    ],
  },
  optimization: {
    minimizer: [
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.squooshMinify,
          options: {
            encodeOptions: {
              mozjpeg: {
                // That setting might be close to lossless, but it’s not guaranteed
                // https://github.com/GoogleChromeLabs/squoosh/issues/85
                quality: 100,
              },
              webp: {
                lossless: 1,
              },
              avif: {
                // https://github.com/GoogleChromeLabs/squoosh/blob/dev/codecs/avif/enc/README.md
                cqLevel: 0,
              },
            },
          },
        },
      }),
    ],
  },
};

Advanced setup

If you want to use loader or plugin standalone see sections below, but this is not recommended.

By default, plugin configures loader (please use the loader option if you want to disable this behaviour), therefore you should not setup standalone loader when you use a plugin setup.

Loader optimizes or generates images using options, so inlined images via data URI (i.e. data:) will be optimized or generated too, not inlined images will be optimized too.

Standalone Loader

Documentation: Using loaders.

In your webpack.config.js, add the ImageMinimizerPlugin.loader and specify the asset modules options (if you use images in import):

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  module: {
    rules: [
      // You need this, if you are using `import file from "file.ext"`, for `new URL(...)` syntax you don't need it
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        type: "asset",
      },
      // We recommend using only for the "production" mode
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        use: [
          {
            loader: ImageMinimizerPlugin.loader,
            enforce: "pre",
            options: {
              minimizer: {
                implementation: ImageMinimizerPlugin.imageminMinify,
                options: {
                  plugins: [
                    "imagemin-gifsicle",
                    "imagemin-mozjpeg",
                    "imagemin-pngquant",
                    "imagemin-svgo",
                  ],
                },
              },
            },
          },
        ],
      },
    ],
  },
};

Standalone Plugin

Documentation: Using plugins.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  module: {
    rules: [
      // You need this, if you are using `import file from "file.ext"`, for `new URL(...)` syntax you don't need it
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        type: "asset",
      },
    ],
  },
  optimization: {
    minimizer: [
      // Extend default minimizer, i.e. `terser-webpack-plugin` for JS
      "...",
      // We recommend using only for the "production" mode
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [
              "imagemin-gifsicle",
              "imagemin-mozjpeg",
              "imagemin-pngquant",
              "imagemin-svgo",
            ],
          },
        },
        // Disable `loader`
        loader: false,
      }),
    ],
  },
};

Options

Plugin Options

Name Type Default Description
test {String\/RegExp\|Array<String\|RegExp>} /.(jpe?g|png|gif|tif|webp|svg|avif)$/i Test to match files against
include {String\/RegExp\|Array<String\|RegExp>} undefined Files to include
exclude {String\/RegExp\|Array<String\|RegExp>} undefined Files to exclude
minimizer {Object \| Array<Object>} undefined Allows to setup default minimizer
generator {Array<Object>} undefined Allow to setup default generators
severityError {String} 'error' Allows to choose how errors are displayed
loader {Boolean} true Automatically adding built-in loader
concurrency {Number} Math.max(1, os.cpus().length - 1) Maximum number of concurrency optimization processes in one time
deleteOriginalAssets {Boolean} true Allows to delete the original asset for minimizer

test

Type: String|RegExp|Array<String|RegExp> Default: /\.(jpe?g\|png\|gif\|tif\|webp\|svg\|avif)\$/i

Test to match files against.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        test: /\.(jpe?g|png|gif|svg)$/i,
      }),
    ],
  },
};

include

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

Files to include.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        include: /\/includes/,
      }),
    ],
  },
};

exclude

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

Files to exclude.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        exclude: /\/excludes/,
      }),
    ],
  },
};

minimizer

Type: Object|Array<Object> Default: undefined

Allows to setup default minify function.

Available minimizers:

  • ImageMinimizerPlugin.imageminMinify
  • ImageMinimizerPlugin.squooshMinify
Object

For imagemin:

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          // Implementation
          implementation: ImageMinimizerPlugin.imageminMinify,
          // Options
          options: {
            plugins: [
              "imagemin-gifsicle",
              "imagemin-mozjpeg",
              "imagemin-pngquant",
              "imagemin-svgo",
            ],
          },
        },
      }),
    ],
  },
};

More information and examples here.

For squoosh:

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          // Implementation
          implementation: ImageMinimizerPlugin.squooshMinify,
          // Options
          options: {
            encodeOptions: {
              mozjpeg: {
                quality: 90,
              },
            },
          },
        },
      }),
    ],
  },
};

More information and examples here.

Minimizer option list:

implementation

Type: Function Default: undefined

Configure the default implementation.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          // Implementation
          implementation: ImageMinimizerPlugin.squooshMinify,
        },
      }),
    ],
  },
};
options

Type: Object Default: undefined

Options for the implementation option (i.e. options for imagemin/squoosh/custom implementation).

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.squooshMinify,
          // Options
          options: {
            encodeOptions: {
              mozjpeg: {
                quality: 90,
              },
            },
          },
        },
      }),
    ],
  },
};
filter

Type: Function Default: () => true

Allows filtering of images for optimization/generation.

Return true to optimize the image, false otherwise.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          filter: (source, sourcePath) => {
            // The `source` argument is a `Buffer` of source file
            // The `sourcePath` argument is an absolute path to source
            if (source.byteLength < 8192) {
              return false;
            }

            return true;
          },
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [
              "imagemin-gifsicle",
              "imagemin-mozjpeg",
              "imagemin-pngquant",
              "imagemin-svgo",
            ],
          },
        },
      }),
    ],
  },
};
filename

Type: string | Function Default: undefined

Allows to set the filename. Supported values see in webpack template strings, File-level section.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          filename: "optimized-[name][ext]",
          implementation: ImageMinimizerPlugin.squooshMinify,
          // Options
          options: {
            encodeOptions: {
              mozjpeg: {
                quality: 90,
              },
            },
          },
        },
      }),
    ],
  },
};

Example Function usage:

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          filename: () => "optimized-[name][ext]",
          implementation: ImageMinimizerPlugin.squooshMinify,
          // Options
          options: {
            encodeOptions: {
              mozjpeg: {
                quality: 90,
              },
            },
          },
        },
      }),
    ],
  },
};
Array

Allows to setup multiple minimizers.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: [
          {
            implementation: ImageMinimizerPlugin.imageminMinify,
            options: {
              plugins: [
                "imagemin-gifsicle",
                "imagemin-mozjpeg",
                "imagemin-pngquant",
                "imagemin-svgo",
              ],
            },
          },
          {
            implementation: (original, options) => {
              let result;

              try {
                result = minifyAndReturnBuffer(original.data);
              } catch (error) {
                // Return original input if there was an error
                return {
                  filename: original.filename,
                  data: original.data,
                  errors: [error],
                  warnings: [],
                };
              }

              return {
                filename: original.filename,
                data: result,
                warnings: [],
                errors: [],
                info: {
                  // Please always set it to prevent double minification
                  minimized: true,
                  // Optional
                  minimizedBy: ["custom-name-of-minimication"],
                },
              };
            },
            options: {
              // Custom options
            },
          },
        ],
      }),
    ],
  },
};

generator

Type: Array<Object> Default: undefined

Allow to setup default generators. Useful if you need generate webp/avif/etc from other formats.

⚠️ If no generator was found for the image (i.e. no ?as=webp was found in query params), the minimizer option will be used. Therefore, it is recommended to configure generator outputs optimized image. ⚠️ The option will not work if you disable loader (i.e. set the loader option to false).

Available generators:

  • ImageMinimizerPlugin.imageminGenerate
  • ImageMinimizerPlugin.squooshGenerate

Example webp generator:

  • imagemin

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            // You can apply generator using `?as=webp`, you can use any name and provide more options
            preset: "webp",
            implementation: ImageMinimizerPlugin.imageminGenerate,
            options: {
              // Please specify only one plugin here, multiple plugins will not work
              plugins: ["imagemin-webp"],
            },
          },
        ],
      }),
    ],
  },
};
  • squoosh

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            // You can apply generator using `?as=webp`, you can use any name and provide more options
            preset: "webp",
            implementation: ImageMinimizerPlugin.squooshGenerate,
            options: {
              encodeOptions: {
                // Please specify only one codec here, multiple codecs will not work
                webp: {
                  quality: 90,
                },
              },
            },
          },
        ],
      }),
    ],
  },
};

Now you can generate the new image using:

// Old approach for getting URL
import webp from "./file.jpg?as=webp";

// Assets modules
console.log(new URL("./file.jpg?as=webp"));
div {
  background: url("./file.jpg?as=webp");
}

You can use ?as=webp in any type of files.

Example multiple generators:

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            // You can apply generator using `?as=webp`, you can use any name and provide more options
            preset: "webp",
            implementation: ImageMinimizerPlugin.squooshGenerate,
            options: {
              encodeOptions: {
                webp: {
                  quality: 90,
                },
              },
            },
          },
          {
            // You can apply generator using `?as=avif`, you can use any name and provide more options
            preset: "avif",
            implementation: ImageMinimizerPlugin.squooshGenerate,
            options: {
              encodeOptions: {
                avif: {
                  cqLevel: 33,
                },
              },
            },
          },
        ],
      }),
    ],
  },
};

squoosh generator supports more options, for example you can resize an image:

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            // You can apply generator using `?as=webp-100-50`, you can use any name and provide more options
            preset: "webp-100-50",
            implementation: ImageMinimizerPlugin.squooshGenerate,
            options: {
              encodeOptions: {
                resize: {
                  enabled: true,
                  width: 100,
                  height: 50,
                },
                webp: {
                  quality: 90,
                },
              },
            },
          },
        ],
      }),
    ],
  },
};

You can find more information here.

You can use your own generator implementation.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            // You can apply generator using `?as=webp`, you can use any name and provide more options
            preset: "webp",
            implementation: (original, options) => {
              let result;

              try {
                result = minifyAndReturnBuffer(original.data);
              } catch (error) {
                // Return original input if there was an error
                return {
                  filename: original.filename,
                  data: original.data,
                  errors: [error],
                  warnings: [],
                };
              }

              return {
                filename: original.filename,
                data: result,
                warnings: [],
                errors: [],
                info: {
                  // Please always set it to prevent double minification
                  generated: true,
                  // Optional
                  generatedBy: ["custom-name-of-minimication"],
                },
              };
            },
            options: {
              // Your options
            },
          },
        ],
      }),
    ],
  },
};

Generator option list:

type

Type: "import" | "asset" Default: "import"

Allows you to apply the generator for import or assets from compilation (useful for copied assets). By default, generators are applying on import/require, but sometimes you need to generate new images from other plugins (for example - copy-webpack-plugin), if you need this, please set asset value for the type option.

webpack.config.js

const CopyPlugin = require("copy-webpack-plugin");
const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [
              "imagemin-gifsicle",
              "imagemin-mozjpeg",
              "imagemin-pngquant",
              "imagemin-svgo",
            ],
          },
        },
        generator: [
          {
            // Apply generator for copied assets
            type: "asset",
            // You can use `ImageMinimizerPlugin.squooshGenerate`
            implementation: ImageMinimizerPlugin.imageminGenerate,
            options: {
              plugins: ["imagemin-webp"],
            },
          },
        ],
      }),
    ],
  },
  plugnins: [new CopyPlugin({ patterns: ["images/**/*.png"] })],
};
preset

Type: String Default: undefined

Configure the name of preset, i.e. you can use it in ?as=name.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            preset: "name",
            // Implementation
            implementation: ImageMinimizerPlugin.squooshMinify,
          },
        ],
      }),
    ],
  },
};
implementation

Type: Function Default: undefined

Configure the default implementation.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            preset: "name",
            // Implementation
            implementation: ImageMinimizerPlugin.squooshMinify,
          },
        ],
      }),
    ],
  },
};
options

Type: Object Default: undefined

Options for the implementation option (i.e. options for imagemin/squoosh/custom implementation).

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            preset: "name",
            implementation: ImageMinimizerPlugin.squooshMinify,
            // Options
            options: {
              encodeOptions: {
                mozjpeg: {
                  quality: 90,
                },
              },
            },
          },
        ],
      }),
    ],
  },
};
filter

Type: Function Default: () => true

Allows filtering of images for optimization/generation.

Return true to optimize the image, false otherwise.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            preset: "name",
            filter: (source, sourcePath) => {
              // The `source` argument is a `Buffer` of source file
              // The `sourcePath` argument is an absolute path to source
              if (source.byteLength < 8192) {
                return false;
              }

              return true;
            },
            implementation: ImageMinimizerPlugin.imageminMinify,
            options: {
              plugins: [
                "imagemin-gifsicle",
                "imagemin-mozjpeg",
                "imagemin-pngquant",
                "imagemin-svgo",
              ],
            },
          },
        ],
      }),
    ],
  },
};
filename

Type: string | Function Default: undefined

Allows to set the filename. Supported values see in webpack template strings, File-level section.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            preset: "name",
            filename: "generated-[name][ext]",
            implementation: ImageMinimizerPlugin.squooshMinify,
            // Options
            options: {
              encodeOptions: {
                mozjpeg: {
                  quality: 90,
                },
              },
            },
          },
        ],
      }),
    ],
  },
};

Example of Function usage:

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        generator: [
          {
            preset: "name",
            filename: () => "generated-[name][ext]",
            implementation: ImageMinimizerPlugin.squooshMinify,
            // Options
            options: {
              encodeOptions: {
                mozjpeg: {
                  quality: 90,
                },
              },
            },
          },
        ],
      }),
    ],
  },
};

severityError

Type: String Default: 'error'

Allows to choose how errors are displayed.

Сan have the following values:

  • 'off' - suppresses errors and warnings
  • 'warning' - emit warnings instead errors
  • 'error' - emit errors

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        severityError: "warning",
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [
              "imagemin-gifsicle",
              "imagemin-mozjpeg",
              "imagemin-pngquant",
              "imagemin-svgo",
            ],
          },
        },
      }),
    ],
  },
};

loader

Type: Boolean Default: true

Automatically adding built-in loader, used to optimize/generate images.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        loader: false,
        // `generator` will not work in this case
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [
              "imagemin-gifsicle",
              "imagemin-mozjpeg",
              "imagemin-pngquant",
              "imagemin-svgo",
            ],
          },
        },
      }),
    ],
  },
};

concurrency

Type: Number Default: Math.max(1, os.cpus().length - 1)

Maximum number of concurrency optimization processes in one time.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        concurrency: 3,
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [
              "imagemin-gifsicle",
              "imagemin-mozjpeg",
              "imagemin-pngquant",
              "imagemin-svgo",
            ],
          },
        },
      }),
    ],
  },
};

deleteOriginalAssets

Type: Boolean Default: true

Allows removing original assets after optimization.

Please use this option if you are set the filename option for the minimizer option, disable loader: false and want to keep optimized and not optimized assets.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        // Disable loader
        loader: false,
        // Allows to keep original asset and minimized assets with different filenames
        deleteOriginalAssets: false,
        minimizer: {
          filename: "[path][name].webp",
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [
              "imagemin-gifsicle",
              "imagemin-mozjpeg",
              "imagemin-pngquant",
              "imagemin-svgo",
            ],
          },
        },
      }),
    ],
  },
};

Loader Options

Name Type Default Description
minimizer {Object \| Array<Object>} undefined Allows to setup default minimizer
generator {Array<Object>} undefined Allows to setup default generator
severityError {String} 'error' Allows to choose how errors are displayed

severityError

Type: String Default: 'error'

Allows to choose how errors are displayed.

Сan have the following values:

  • 'off' - suppresses errors and warnings
  • 'warning' - emit warnings instead errors
  • 'error' - emit errors

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  module: {
    rules: [
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        type: "asset",
      },
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        use: [
          {
            loader: ImageMinimizerPlugin.loader,
            options: {
              severityError: "warning",
              minimizerOptions: {
                plugins: ["gifsicle"],
              },
            },
          },
        ],
      },
    ],
  },
};

minimizer

Type: Object|Array<Object> Default: undefined

Allows to setup default minimizer.

Object

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  module: {
    rules: [
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        type: "asset",
      },
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        loader: ImageMinimizerPlugin.loader,
        enforce: "pre",
        options: {
          minimizer: {
            implementation: ImageMinimizerPlugin.squooshMinify,
            options: {
              // Your options
            },
          },
        },
      },
    ],
  },
};

For more information and supported options please read here.

generator

Type: Array<Object> Default: undefined

Allow to setup default generators. Useful if you need generate webp/avif/etc from other formats.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  module: {
    rules: [
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        type: "asset",
      },
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        loader: ImageMinimizerPlugin.loader,
        enforce: "pre",
        options: {
          generator: [
            {
              preset: "webp",
              implementation: ImageMinimizerPlugin.imageminGenerate,
              options: {
                plugins: ["iamgemin-webp"],
              },
            },
          ],
        },
      },
    ],
  },
};

For more information and supported options please read here.

Additional API

imageminNormalizeConfig(config)

The function normalizes configuration (converts plugins names and options to Functions) for using in imagemin package directly.

const imagemin = require("imagemin");
const { imageminNormalizeConfig } = require("image-minimizer-webpack-plugin");

/*
  console.log(imageminConfig);
  =>
  {
    plugins: [Function, Function],
    pluginsMeta: [
      { name: "imagemin-jpegtran", version: "x.x.x", options: {} },
      { name: "imagemin-pngquant", version: "x.x.x", options: { quality: [0.6, 0.8] }
    ]
  }
*/

(async () => {
  const imageminConfig = await imageminNormalizeConfig({
    plugins: ["jpegtran", ["pngquant", { quality: [0.6, 0.8] }]],
  });
  const files = await imagemin(["images/*.{jpg,png}"], {
    destination: "build/images",
    plugins: imageminConfig.plugins,
  });

  console.log(files);
  // => [{data: <Buffer 89 50 4e …>, path: 'build/images/foo.jpg'}, …]
})();

Examples

Optimize images based on size

You can use difference options (like progressive/interlaced/etc.) based on image size (example - don't do progressive transformation for small images).

What is progressive image? Answer here.

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [["jpegtran", { progressive: true }]],
          },
          // Only apply this one to files equal to or over 8192 bytes
          filter: (source) => {
            if (source.byteLength >= 8192) {
              return true;
            }

            return false;
          },
        },
      }),
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [["jpegtran", { progressive: false }]],
          },
          // Only apply this one to files under 8192
          filter: (source) => {
            if (source.byteLength < 8192) {
              return true;
            }

            return false;
          },
        },
      }),
    ],
  },
};

Optimize and generate webp images

  • imagemin

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [
              "imagemin-gifsicle",
              "imagemin-mozjpeg",
              "imagemin-pngquant",
              "imagemin-svgo",
            ],
          },
        },
        generator: [
          {
            // You can apply generator using `?as=webp`, you can use any name and provide more options
            preset: "webp",
            implementation: ImageMinimizerPlugin.imageminGenerate,
            options: {
              plugins: ["imagemin-webp"],
            },
          },
        ],
      }),
    ],
  },
};
  • squoosh

webpack.config.js

const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.squooshMinify,
        },
        generator: [
          {
            // You can apply generator using `?as=webp`, you can use any name and provide more options
            preset: "webp",
            implementation: ImageMinimizerPlugin.squooshGenerate,
            options: {
              encodeOptions: {
                webp: {
                  quality: 90,
                },
              },
            },
          },
        ],
      }),
    ],
  },
};

Generate webp images from copied assets

  • imagemin

webpack.config.js

const CopyPlugin = require("copy-webpack-plugin");
const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [
              "imagemin-gifsicle",
              "imagemin-mozjpeg",
              "imagemin-pngquant",
              "imagemin-svgo",
            ],
          },
        },
        generator: [
          {
            type: "asset",
            implementation: ImageMinimizerPlugin.imageminGenerate,
            options: {
              plugins: ["imagemin-webp"],
            },
          },
        ],
      }),
    ],
  },
  plugnins: [new CopyPlugin({ patterns: ["images/**/*.png"] })],
};
  • squoosh

webpack.config.js

const CopyPlugin = require("copy-webpack-plugin");
const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");

module.exports = {
  optimization: {
    minimizer: [
      "...",
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.squooshMinify,
        },
        generator: [
          {
            type: "asset",
            implementation: ImageMinimizerPlugin.squooshGenerate,
            options: {
              encodeOptions: {
                webp: {
                  quality: 90,
                },
              },
            },
          },
        ],
      }),
    ],
  },
  plugnins: [new CopyPlugin({ patterns: ["images/**/*.png"] })],
};

Contributing

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

CONTRIBUTING

License

MIT