[![npm][npm]][npm-url]
[![node][node]][node-url]
[![tests][tests]][tests-url]
[![cover][cover]][cover-url]
[![discussion][discussion]][discussion-url]
[![size][size]][size-url]

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.

This plugin integrates seamlessly into your Webpack build pipeline to reduce HTML size and improve loading performance.

Getting Started

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

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

or

`console
yarn add -D html-minimizer-webpack-plugin
`

or

`console
pnpm add -D html-minimizer-webpack-plugin
`

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

`console
npm install @swc/html --save-dev
`

or

`console
yarn add -D @swc/html
`

or

`console
pnpm add -D @swc/html
`

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

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

or

`console
yarn add -D @minify-html/node
`

or

`console
pnpm add -D @minify-html/node
`

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

webpack.config.js

`js
const CopyPlugin = require("copy-webpack-plugin");
const HtmlMinimizerPlugin = require("html-minimizer-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 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: {}
// })
],
},
};
``

> [!NOTE]
>
> HTML will only be minimized in production mode by default. To enable minification in development, explicitly set optimization.minimize: true.

Finally, run webpack using the method you normally use (e.g., via CLI or an npm script).

> [!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 for detailed whitespace behavior.

Options

- test
- include
- exclude
- parallel
- minify
- minimizerOptions

$3

Type:

`ts
type test = string | RegExp | (string | RegExp)[];
`

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

Test to match files against.

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

$3

Type:

`ts
type include = string | RegExp | (string | RegExp)[];
`

Default: undefined

Files to include for minification.

webpack.config.js

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

$3

Type:

`ts
type exclude = string | RegExp | (string | RegExp)[];
`

Default: undefined

Files to exclude from minification.

webpack.config.js

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

$3

Type:

`ts
type parallel = undefined | boolean | number;
`

Default: true

Enables multi-process parallelization to improve build performance.

- If true, uses os.cpus().length - 1 or os.availableParallelism() - 1 (if available).

- If number, sets the number of concurrent workers.

> [!NOTE]
>
> Parallelization can speed up your build significantly and is therefore highly recommended.

#### boolean

Enable or disable multi-process parallel running.

webpack.config.js

`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

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

$3

Type:

`ts
type minify =
| ((
data: Record,
minimizerOptions: Record,
) => {
code: string;
errors?: unknown[] | undefined;
warnings?: unknown[] | undefined;
})
| ((
data: Record,
minimizerOptions: Record,
) => {
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

You can define a custom minify function, giving full control over how the HTML is processed.

webpack.config.js

`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 either as:

- An array; If minimizerOptions is array, the function index in the minify array corresponds to the options object with the same index in the minimizerOptions array.

- A single object; If you use minimizerOptions like object, all minify function accept it.

webpack.config.js

`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: [],
};
},
],
}),
],
},
};
`

$3

Type:

`ts
type minimizerOptions = Record | Record[];
`

Default:

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

Html-minifier-terser optimizations options.

#### object

Applies the same options to the default or custom minify function.

`js
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

`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

$3

Available options.

HTML Documents:

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

Use this for partial HTML files (e.g. inside tags or HTML strings).

`js
const path = require("node:path");
const CopyPlugin = require("copy-webpack-plugin");
const HtmlMinimizerPlugin = require("html-minimizer-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
},
}),
],
},
};
`

$3

Available options.

HTML Documents:

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

We welcome all contributions!
If you're new here, please take a moment to review our contributing guidelines before submitting issues or pull requests.

CONTRIBUTING

License

MIT

[npm]: https://img.shields.io/npm/v/html-minimizer-webpack-plugin.svg
[npm-url]: https://npmjs.com/package/html-minimizer-webpack-plugin
[node]: https://img.shields.io/node/v/html-minimizer-webpack-plugin.svg
[node-url]: https://nodejs.org
[tests]: https://github.com/webpack/html-minimizer-webpack-plugin/workflows/html-minimizer-webpack-plugin/badge.svg
[tests-url]: https://github.com/webpack/html-minimizer-webpack-plugin/actions
[cover]: https://codecov.io/gh/webpack/html-minimizer-webpack-plugin/branch/main/graph/badge.svg
[cover-url]: https://codecov.io/gh/webpack/html-minimizer-webpack-plugin
[discussion]: https://img.shields.io/github/discussions/webpack/webpack
[discussion-url]: https://github.com/webpack/webpack/discussions
[size]: https://packagephobia.now.sh/badge?p=html-minimizer-webpack-plugin
[size-url]: https://packagephobia.now.sh/result?p=html-minimizer-webpack-plugin