html-minimizer-webpack-plugin

This plugin can use 3 tools to optimize and minify your HTML:

• swc - very fast Rust-based platform for the Web.
• html-minifier-terser (by default) - JavaScript-based HTML minifier.
• @minify-html/node - A Rust HTML minifier meticulously optimised for speed and effectiveness, with bindings for other languages.

Getting Started

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

npm install html-minimizer-webpack-plugin --save-dev

or

yarn add -D html-minimizer-webpack-plugin

or

pnpm add -D html-minimizer-webpack-plugin

Additional step: If you want to use @swc/html you need to install it:

npm install @swc/html --save-dev

or

yarn add -D @swc/html

or

pnpm add -D @swc/html

Additional step: If you want to use @minify-html/node you need to install it:

npm install @minify-html/node --save-dev

or

yarn add -D @minify-html/node

or

pnpm add -D @minify-html/node

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

webpack.config.js

const HtmlMinimizerPlugin = require("html-minimizer-webpack-plugin");
const CopyPlugin = require("copy-webpack-plugin");

module.exports = {
  module: {
    rules: [
      {
        test: /\.html$/i,
        type: "asset/resource",
      },
    ],
  },
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          context: path.resolve(__dirname, "dist"),
          from: "./src/*.html",
        },
      ],
    }),
  ],
  optimization: {
    minimize: true,
    minimizer: [
      // For webpack@5 you can use the `...` syntax to extend existing minimizers (i.e. `terser-webpack-plugin`), uncomment the next line
      // `...`

      // For `html-minifier-terser`:
      //
      new HtmlMinimizerPlugin(),

      // For `@swc/html`:
      //
      // HTML documents - HTML documents with `Doctype` and `/``/`` tags
      //
      // Options - https://github.com/swc-project/bindings/blob/main/packages/html/index.ts#L5
      //
      // new HtmlMinimizerPlugin({
      //   minify: HtmlMinimizerPlugin.swcMinify,
      //   minimizerOptions: {}
      // })
      //
      //
      // HTML fragments - HTML fragments, i.e. HTML files without doctype or used in `<template>` tags or HTML parts which injects into another HTML parts
      //
      // Options - https://github.com/swc-project/bindings/blob/main/packages/html/index.ts#L38
      //
      // new HtmlMinimizerPlugin({
      //   minify: HtmlMinimizerPlugin.swcMinifyFragment,
      //   minimizerOptions: {}
      // })
    ],
  },
};

This will enable HTML optimization only in production mode. If you want to run it also in development set the optimization.minimize option to true.

And run webpack via your preferred method.

> Note > > Removing and collapsing spaces in the tools differ (by default). > > - @swc/html - remove and collapse whitespaces only in safe places (for example - around html and body elements, inside the head element and between metadata elements - ``/script/link/etc.) > - html-minifier-terser - always collapse multiple whitespaces to 1 space (never remove it entirely), but you can change it using options > - @minify-html/node - please read documentation https://github.com/wilsonzlin/minify-html#whitespace

Options

• test
• include
• exclude
• parallel
• minify
• minimizerOptions

test

Type:

type test = string | RegExp | Array;

Default: /\.html(\?.*)?$/i

Test to match files against.

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new HtmlMinimizerPlugin({
        test: /\.foo\.html/i,
      }),
    ],
  },
};

include

Type:

type include = string | RegExp | Array;

Default: undefined

Files to include.

webpack.config.js

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

exclude

Type:

type exclude = string | RegExp | Array;

Default: undefined

Files to exclude.

webpack.config.js

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

parallel

Type:

type parallel = undefined | boolean | number;

Default: true

Use multi-process parallel running to improve the build speed. Default number of concurrent runs: os.cpus().length - 1.

> Note > > Parallelization can speed up your build significantly and is therefore highly recommended.

boolean

Enable/disable multi-process parallel running.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new HtmlMinimizerPlugin({
        parallel: true,
      }),
    ],
  },
};

number

Enable multi-process parallel running and set number of concurrent runs.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new HtmlMinimizerPlugin({
        parallel: 4,
      }),
    ],
  },
};

minify

Type:

type minify =
  | ((
      data: { [file: string]: string },
      minimizerOptions: {
        [key: string]: any;
      },
    ) => {
      code: string;
      errors?: unknown[] | undefined;
      warnings?: unknown[] | undefined;
    })
  | ((
      data: { [file: string]: string },
      minimizerOptions: {
        [key: string]: any;
      },
    ) => {
      code: string;
      errors?: unknown[] | undefined;
      warnings?: unknown[] | undefined;
    })[];

Default: HtmlMinimizerPlugin.htmlMinifierTerser

Allows you to override default minify function. By default, plugin uses html-minifier-terser package.

We currently support:

• HtmlMinimizerPlugin.swcMinify (used to compress HTML documents, i.e. with HTML doctype and //`` tags)
• HtmlMinimizerPlugin.swcMinifyFragment (used to compress HTML fragments, i.e. when you have part of HTML which will be inserted into another HTML parts)
• HtmlMinimizerPlugin.htmlMinifierTerser
• HtmlMinimizerPlugin.minifyHtmlNode

> Note > > The difference between swcMinify and swcMinifyFragment is the error reporting. > You will get errors (invalid or broken syntax) if you have them in your HTML document or fragment. Which allows you to see all the errors and problems at the build stage.

Useful for using and testing unpublished versions or forks.

> Warning > > Always use require inside minify function when parallel option enabled.

function

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new HtmlMinimizerPlugin({
        minimizerOptions: {
          collapseWhitespace: true,
        },
        minify: (data, minimizerOptions) => {
          const htmlMinifier = require("html-minifier-terser");
          const [[filename, input]] = Object.entries(data);

          return {
            code: htmlMinifier.minify(input, minimizerOptions),
            warnings: [],
            errors: [],
          };
        },
      }),
    ],
  },
};

array

If an array of functions is passed to the minify option, the minimizerOptions can be an array or an object. If minimizerOptions is array, the function index in the minify array corresponds to the options object with the same index in the minimizerOptions array. If you use minimizerOptions like object, all minify function accept it.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new HtmlMinimizerPlugin({
        minimizerOptions: [
          // Options for the first function (HtmlMinimizerPlugin.htmlMinifierTerser)
          {
            collapseWhitespace: true,
          },
          // Options for the second function
          {},
        ],
        minify: [
          HtmlMinimizerPlugin.htmlMinifierTerser,
          (data, minimizerOptions) => {
            const [[filename, input]] = Object.entries(data);
            // To do something
            return {
              code: `optimised code`,
              warnings: [],
              errors: [],
            };
          },
        ],
      }),
    ],
  },
};

minimizerOptions

Type:

type minimizerOptions =
  | {
      [key: string]: any;
    }
  | Array<{
      [key: string]: any;
    }>;

Default: { caseSensitive: true, collapseWhitespace: true, conservativeCollapse: true, keepClosingSlash: true, minifyCSS: true, minifyJS: true, removeComments: true, removeScriptTypeAttributes: true, removeStyleLinkTypeAttributes: true, }

Html-minifier-terser optimizations options.

object

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new HtmlMinimizerPlugin({
        minimizerOptions: {
          collapseWhitespace: false,
        },
      }),
    ],
  },
};

array

The function index in the minify array corresponds to the options object with the same index in the minimizerOptions array. If you use minimizerOptions like object, all minify function accept it.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new HtmlMinimizerPlugin({
        minimizerOptions: [
          // Options for the first function (HtmlMinimizerPlugin.htmlMinifierTerser)
          {
            collapseWhitespace: true,
          },
          // Options for the second function
          {},
        ],
        minify: [
          HtmlMinimizerPlugin.htmlMinifierTerser,
          (data, minimizerOptions) => {
            const [[filename, input]] = Object.entries(data);
            // To do something
            return {
              code: `optimised code`,
              warnings: [],
              errors: [],
            };
          },
        ],
      }),
    ],
  },
};

Examples

swc/html

Available options.

HTML Documents:

const HtmlMinimizerPlugin = require("html-minimizer-webpack-plugin");
const CopyPlugin = require("copy-webpack-plugin");

module.exports = {
  module: {
    rules: [
      {
        test: /\.html$/i,
        type: "asset/resource",
      },
    ],
  },
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          context: path.resolve(__dirname, "dist"),
          from: "./src/*.html",
        },
      ],
    }),
  ],
  optimization: {
    minimize: true,
    minimizer: [
      new HtmlMinimizerPlugin({
        minify: HtmlMinimizerPlugin.swcMinify,
        minimizerOptions: {
          // Options - https://github.com/swc-project/bindings/blob/main/packages/html/index.ts#L5
        },
      }),
    ],
  },
};

HTML Fragments:

const HtmlMinimizerPlugin = require("html-minimizer-webpack-plugin");
const CopyPlugin = require("copy-webpack-plugin");

module.exports = {
  module: {
    rules: [
      {
        test: /\.html$/i,
        type: "asset/resource",
      },
    ],
  },
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          context: path.resolve(__dirname, "dist"),
          from: "./src/*.html",
        },
      ],
    }),
  ],
  optimization: {
    minimize: true,
    minimizer: [
      new HtmlMinimizerPlugin({
        test: /\.template\.html$/i,
        minify: HtmlMinimizerPlugin.swcMinifyFragment,
        minimizerOptions: {
          // Options - https://github.com/swc-project/bindings/blob/main/packages/html/index.ts#L38
        },
      }),
    ],
  },
};

@minify-html/node

Available options.

HTML Documents:

const HtmlMinimizerPlugin = require("html-minimizer-webpack-plugin");
const CopyPlugin = require("copy-webpack-plugin");

module.exports = {
  module: {
    rules: [
      {
        test: /\.html$/i,
        type: "asset/resource",
      },
    ],
  },
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          context: path.resolve(__dirname, "dist"),
          from: "./src/*.html",
        },
      ],
    }),
  ],
  optimization: {
    minimize: true,
    minimizer: [
      new HtmlMinimizerPlugin({
        minify: HtmlMinimizerPlugin.minifyHtmlNode,
        minimizerOptions: {
          // Options - https://github.com/wilsonzlin/minify-html#minification
        },
      }),
    ],
  },
};

You can use multiple HtmlMinimizerPlugin plugins to compress different files with the different minify function.

Contributing

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

CONTRIBUTING

License

MIT