html-webpack-plugin

What is html-webpack-plugin?

The html-webpack-plugin is a plugin for webpack that simplifies the creation of HTML files to serve your webpack bundles. It is especially useful for webpack bundles that include a hash in the filename which changes every compilation. You can let the plugin generate an HTML file for you, include your webpack bundles in the file, or generate multiple HTML files with different configurations.

What are html-webpack-plugin's main functionalities?

Generating a default HTML file

This feature automatically generates a default HTML file that includes all your webpack bundles.

const HtmlWebpackPlugin = require('html-webpack-plugin');

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

Custom template

This feature allows you to provide a custom HTML template for the generated file.

const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
  plugins: [
    new HtmlWebpackPlugin({
      template: 'src/index.html'
    })
  ]
};

Injecting assets

This feature automatically injects all necessary webpack bundles into the HTML file.

const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
  plugins: [
    new HtmlWebpackPlugin({
      inject: true
    })
  ]
};

Generating multiple HTML files

This feature allows you to generate multiple HTML files with different names and templates.

const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
  plugins: [
    new HtmlWebpackPlugin({
      filename: 'index.html',
      template: 'src/index.html'
    }),
    new HtmlWebpackPlugin({
      filename: 'about.html',
      template: 'src/about.html'
    })
  ]
};

Other packages similar to html-webpack-plugin

html-webpack-template

This package provides a pluggable template for the html-webpack-plugin, offering additional features like meta tags, links to CDN-hosted libraries, and more. It is more opinionated than the base html-webpack-plugin, which allows for more customization.

webpack-pwa-manifest

This is a webpack plugin that generates a 'manifest.json' for your Progressive Web Application, with auto icon resizing and fingerprinting support. It serves a different purpose than html-webpack-plugin but is often used alongside it to set up web app manifests.

favicons-webpack-plugin

This plugin for webpack uses the favicons library to automatically generate favicons for different platforms and insert them into an HTML file generated by html-webpack-plugin. It complements the html-webpack-plugin by managing favicon generation.

README

HTML Webpack Plugin

Plugin that simplifies creation of HTML files to serve your bundles

Install

  npm i --save-dev html-webpack-plugin

  yarn add --dev html-webpack-plugin

This is a webpack plugin that simplifies creation of HTML files to serve your webpack bundles. This is especially useful for webpack bundles that include a hash in the filename which changes every compilation. You can either let the plugin generate an HTML file for you, supply your own template using lodash templates or use your own loader.

Plugins

The html-webpack-plugin provides hooks to extend it to your needs. There are already some really powerful plugins which can be integrated with zero configuration

• webpack-subresource-integrity for enhanced asset security
• appcache-webpack-plugin for iOS and Android offline usage
• favicons-webpack-plugin which generates favicons and icons for iOS, Android and desktop browsers
• html-webpack-harddisk-plugin can be used to always write to disk the html file, useful when webpack-dev-server / HMR are being used
• html-webpack-inline-source-plugin to inline your assets in the resulting HTML file
• html-webpack-inline-svg-plugin to inline SVGs in the resulting HTML file.
• html-webpack-exclude-assets-plugin for excluding assets using regular expressions
• html-webpack-include-assets-plugin for including lists of js or css file paths (such as those copied by the copy-webpack-plugin).
• script-ext-html-webpack-plugin to add async, defer or module attributes to your <script> elements, or even inline them
• style-ext-html-webpack-plugin to convert your <link>s to external stylesheets into <style> elements containing internal CSS
• resource-hints-webpack-plugin to add resource hints for faster initial page loads using <link rel='preload'> and <link rel='prefetch'>
• preload-webpack-plugin for automatically wiring up asynchronous (and other types) of JavaScript chunks using <link rel='preload'> helping with lazy-loading
• link-media-html-webpack-plugin allows for injected stylesheet <link /> tags to have their media attribute set automatically; useful for providing specific desktop/mobile/print etc. stylesheets that the browser will conditionally download
• inline-chunk-manifest-html-webpack-plugin for inlining webpack's chunk manifest. Default extracts manifest and inlines in <head>
• html-webpack-inline-style-plugin for inlining styles to HTML elements using juice. Useful for email generation automatisation.
• html-webpack-exclude-empty-assets-plugin removes empty assets from being added to the html. This fixes some problems with extract-text-plugin with webpack 4.
• webpack-concat-plugin for concat and uglify files that needn't to be webpack bundles(for legacy files) and inject to html-webpack-plugin.

Usage

The plugin will generate an HTML5 file for you that includes all your webpack bundles in the body using script tags. Just add the plugin to your webpack config as follows:

webpack.config.js

const HtmlWebpackPlugin = require('html-webpack-plugin')

module.exports = {
  entry: 'index.js',
  output: {
    path: __dirname + '/dist',
    filename: 'index_bundle.js'
  },
  plugins: [
    new HtmlWebpackPlugin()
  ]
}

This will generate a file dist/index.html containing the following

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Webpack App</title>
  </head>
  <body>
    <script src="index_bundle.js"></script>
  </body>
</html>

If you have multiple webpack entry points, they will all be included with script tags in the generated HTML.

If you have any CSS assets in webpack's output (for example, CSS extracted with the ExtractTextPlugin) then these will be included with <link> tags in the HTML head.

If you have plugins that make use of it, html-webpack-plugin should be ordered first before any of the integrated plugins.

Options

You can pass a hash of configuration options to html-webpack-plugin. Allowed values are as follows

Name	Type	Default	Description
title	{String}	``	The title to use for the generated HTML document
filename	{String}	'index.html'	The file to write the HTML to. Defaults to index.html. You can specify a subdirectory here too (eg: assets/admin.html)
template	{String}	``	webpack require path to the template. Please see the docs for details
templateParameters	{Boolean|Object|Function}	``	Allows to overwrite the parameters used in the template
inject	{Boolean|String}	true	true || 'head' || 'body' || false Inject all assets into the given template or templateContent. When passing true or 'body' all javascript resources will be placed at the bottom of the body element. 'head' will place the scripts in the head element
favicon	{String}	``	Adds the given favicon path to the output HTML
meta	{Object}	{}	Allows to inject meta-tags. E.g. meta: {viewport: 'width=device-width, initial-scale=1, shrink-to-fit=no'}
minify	{Boolean|Object}	true	Pass html-minifier's options as object to minify the output
hash	{Boolean}	false	If true then append a unique webpack compilation hash to all included scripts and CSS files. This is useful for cache busting
cache	{Boolean}	true	Emit the file only if it was changed
showErrors	{Boolean}	true	Errors details will be written into the HTML page
chunks	{?}	?	Allows you to add only some chunks (e.g only the unit-test chunk)
chunksSortMode	{String|Function}	auto	Allows to control how chunks should be sorted before they are included to the HTML. Allowed values are 'none' | 'auto' | 'dependency' | 'manual' | {Function}
excludeChunks	{Array.<string>}	``	Allows you to skip some chunks (e.g don't add the unit-test chunk)
xhtml	{Boolean}	false	If true render the link tags as self-closing (XHTML compliant)

Here's an example webpack config illustrating how to use these options

webpack.config.js

{
  entry: 'index.js',
  output: {
    path: __dirname + '/dist',
    filename: 'index_bundle.js'
  },
  plugins: [
    new HtmlWebpackPlugin({
      title: 'My App',
      filename: 'assets/admin.html'
    })
  ]
}

Generating Multiple HTML Files

To generate more than one HTML file, declare the plugin more than once in your plugins array

webpack.config.js

{
  entry: 'index.js',
  output: {
    path: __dirname + '/dist',
    filename: 'index_bundle.js'
  },
  plugins: [
    new HtmlWebpackPlugin(), // Generates default index.html
    new HtmlWebpackPlugin({  // Also generate a test.html
      filename: 'test.html',
      template: 'src/assets/test.html'
    })
  ]
}

Writing Your Own Templates

If the default generated HTML doesn't meet your needs you can supply your own template. The easiest way is to use the template option and pass a custom HTML file. The html-webpack-plugin will automatically inject all necessary CSS, JS, manifest and favicon files into the markup.

plugins: [
  new HtmlWebpackPlugin({
    title: 'Custom template',
    // Load a custom template (lodash by default see the FAQ for details)
    template: 'index.html'
  })
]

index.html

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-type" content="text/html; charset=utf-8"/>
    <title><%= htmlWebpackPlugin.options.title %></title>
  </head>
  <body>
  </body>
</html>

If you already have a template loader, you can use it to parse the template. Please note that this will also happen if you specifiy the html-loader and use .html file as template.

webpack.config.js

module: {
  loaders: [
    { test: /\.hbs$/, loader: "handlebars" }
  ]
},
plugins: [
  new HtmlWebpackPlugin({
    title: 'Custom template using Handlebars',
    template: 'index.hbs'
  })
]

You can use the lodash syntax out of the box. If the inject feature doesn't fit your needs and you want full control over the asset placement use the default template of the html-webpack-template project as a starting point for writing your own.

The following variables are available in the template:

• htmlWebpackPlugin: data specific to this plugin

  • htmlWebpackPlugin.files: a massaged representation of the assetsByChunkName attribute of webpack's stats object. It contains a mapping from entry point name to the bundle filename, eg:

    "htmlWebpackPlugin": {
      "files": {
        "css": [ "main.css" ],
        "js": [ "assets/head_bundle.js", "assets/main_bundle.js"],
        "chunks": {
          "head": {
            "entry": "assets/head_bundle.js",
            "css": [ "main.css" ]
          },
          "main": {
            "entry": "assets/main_bundle.js",
            "css": []
          },
        }
      }
    }
    

    If you've set a publicPath in your webpack config this will be reflected correctly in this assets hash.

  • htmlWebpackPlugin.options: the options hash that was passed to the plugin. In addition to the options actually used by this plugin, you can use this hash to pass arbitrary data through to your template.

• webpack: the webpack stats object. Note that this is the stats object as it was at the time the HTML template was emitted and as such may not have the full set of stats that are available after the webpack run is complete.

• webpackConfig: the webpack configuration that was used for this compilation. This can be used, for example, to get the publicPath (webpackConfig.output.publicPath).

• compilation: the webpack compilation object. This can be used, for example, to get the contents of processed assets and inline them directly in the page, through compilation.assets[...].source() (see the inline template example).

Filtering Chunks

To include only certain chunks you can limit the chunks being used

webpack.config.js

plugins: [
  new HtmlWebpackPlugin({
    chunks: ['app']
  })
]

It is also possible to exclude certain chunks by setting the excludeChunks option

webpack.config.js

plugins: [
  new HtmlWebpackPlugin({
    excludeChunks: [ 'dev-helper' ]
  })
]

Events

To allow other plugins to alter the HTML this plugin executes the following events:

Sync

• html-webpack-plugin-alter-chunks

Async

• html-webpack-plugin-before-html-generation
• html-webpack-plugin-before-html-processing
• html-webpack-plugin-alter-asset-tags
• html-webpack-plugin-after-html-processing
• html-webpack-plugin-after-emit

Example implementation: html-webpack-harddisk-plugin

plugin.js

function MyPlugin(options) {
  // Configure your plugin with options...
}

MyPlugin.prototype.apply = function (compiler) {
  compiler.plugin('compilation', (compilation) => {
    console.log('The compiler is starting a new compilation...');

    compilation.plugin(
      'html-webpack-plugin-before-html-processing',
      (data, cb) => {
        data.html += 'The Magic Footer'

        cb(null, data)
      }
    )
  })
}

module.exports = MyPlugin

webpack.config.js

plugins: [
  new MyPlugin({ options: '' })
]

Note that the callback must be passed the HtmlWebpackPluginData in order to pass this onto any other plugins listening on the same html-webpack-plugin-before-html-processing event

Maintainers

Jan Nicklas

Thomas Sileghem

Contributors

This project exists thanks to all the people who contribute.

You're free to contribute to this project by submitting issues and/or pull requests. This project is test-driven, so keep in mind that every change and new feature should be covered by tests.

This project uses the semistandard code style.

Backers

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Sponsors

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