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

yarn add -D html-minimizer-webpack-plugin

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

yarn add -D @swc/html

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

yarn add -D @minify-html/node

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 `<html>/`<head>`/`<body>` 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 - <meta>/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<string | RegExp>;

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<string | RegExp>;

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<string | RegExp>;

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 <html>/<body>/<head> 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