mini-css-extract-plugin

This plugin extracts CSS into separate files. It creates a CSS file per JS file which contains CSS. It supports On-Demand-Loading of CSS and SourceMaps.

It builds on top of a new webpack v5 feature and requires webpack 5 to work.

Compared to the extract-text-webpack-plugin:

Async loading
No duplicate compilation (performance)
Easier to use
Specific to CSS

Getting Started

To begin, you'll need to install mini-css-extract-plugin:

npm install --save-dev mini-css-extract-plugin

It's recommended to combine mini-css-extract-plugin with the css-loader

Then add the loader and the plugin to your webpack config. For example:

style.css

body {
background: green;
}

component.js

import"./style.css";

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin()],module: {rules: [{test: /\.css$/i,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

Options

Plugin Options

Name	Type	Default	Description
`filename`	`{String\|Function}`	`[name].css`	This option determines the name of each output CSS file
`chunkFilename`	`{String\|Function}`	`based on filename`	This option determines the name of non-entry chunk files
`ignoreOrder`	`{Boolean}`	`false`	Remove Order Warnings
`insert`	`{String\|Function}`	`document.head.appendChild(linkTag);`	Inserts `<link>` at the given position
`attributes`	`{Object}`	`{}`	Adds custom attributes to tag
`linkType`	`{String\|Boolean}`	`text/css`	Allows loading asynchronous chunks with a custom link type
`skipRuntimeLoading`	`{Boolean}`	`false`	Whether skip runtime loading asynchronous chunks
`experimentalUseImportModule`	`{Boolean}`	`false`	Use an experimental webpack API to execute modules instead of child compilers

`filename`

Type: String|Function Default: [name].css

This option determines the name of each output CSS file.

Works like output.filename

`chunkFilename`

Type: String|Function Default: based on filename

i Specifying chunkFilename as a function is only available in webpack@5

This option determines the name of non-entry chunk files.

Works like output.chunkFilename

`ignoreOrder`

Type: Boolean Default: false

Remove Order Warnings. See examples below for details.

`insert`

Type: String|Function Default: document.head.appendChild(linkTag);

By default, the mini-css-extract-plugin appends styles (<link> elements) to document.head of the current window.

However in some circumstances it might be necessary to have finer control over the append target or even delay link elements insertion. For example this is the case when you asynchronously load styles for an application that runs inside of an iframe. In such cases insert can be configured to be a function or a custom selector.

If you target an iframe make sure that the parent document has sufficient access rights to reach into the frame document and append elements to it.

`String`

Allows to setup custom query selector. A new <link> element will be inserted after the found item.

webpack.config.js

newMiniCssExtractPlugin({insert: "#some-element",});

A new <link> element will be inserted after the element with id some-element.

`Function`

Allows to override default behavior and insert styles at any position.

⚠ Do not forget that this code will run in the browser alongside your application. Since not all browsers support latest ECMA features like let, const, arrow function expression and etc we recommend you to use only ECMA 5 features and syntax.

⚠ The insert function is serialized to string and passed to the plugin. This means that it won't have access to the scope of the webpack configuration module.

webpack.config.js

newMiniCssExtractPlugin({insert: function(linkTag){varreference=document.querySelector("#some-element");if(reference){reference.parentNode.insertBefore(linkTag,reference);}},});

A new <link> element will be inserted before the element with id some-element.

`attributes`

Type: Object Default: {}

If defined, the mini-css-extract-plugin will attach given attributes with their values on element.

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({attributes: {id: "target","data-target": "example",},}),],module: {rules: [{test: /\.css$/i,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

Note: It's only applied to dynamically loaded css chunks, if you want to modify link attributes inside html file, please using html-webpack-plugin

`linkType`

Type: String|Boolean Default: text/css

This option allows loading asynchronous chunks with a custom link type, such as <link type="text/css" ...>.

`String`

Possible values: text/css

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({linkType: "text/css",}),],module: {rules: [{test: /\.css$/i,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

`Boolean`

false disables the link type attribute

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({linkType: false,}),],module: {rules: [{test: /\.css$/i,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

`skipRuntimeLoading`

`Boolean`

An option to skip runtime loading asynchronous chunks by the current plugin, and developers can determine when to load by using other plugins.

true to skip.

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({skipRuntimeLoading: true,}),],module: {rules: [{test: /\.css$/i,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

`experimentalUseImportModule`

Use an experimental webpack API to execute modules instead of child compilers.

This improves performance and memory usage a lot, but isn't as stable as the normal approach.

When combined with experiments.layers, this adds a layer option to the loader options to specify the layer of the css execution.

You need to have at least webpack 5.33.2.

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({experimentalUseImportModule: true,}),],module: {rules: [{test: /\.css$/i,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

Loader Options

Name	Type	Default	Description
`publicPath`	`{String\|Function}`	`webpackOptions.output.publicPath`	Specifies a custom public path for the external resources like images, files, etc
`emit`	`{Boolean}`	`true`	If false, the plugin will extract the CSS but will not emit the file
`esModule`	`{Boolean}`	`true`	Use ES modules syntax

`publicPath`

Type: String|Function Default: the publicPath in webpackOptions.output

Specifies a custom public path for the external resources like images, files, etc inside CSS. Works like output.publicPath

`String`

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({// Options similar to the same options in webpackOptions.output// both options are optionalfilename: "[name].css",chunkFilename: "[id].css",}),],module: {rules: [{test: /\.css$/,use: [{loader: MiniCssExtractPlugin.loader,options: {publicPath: "/public/path/to/",},},"css-loader",],},],},};

`Function`

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({// Options similar to the same options in webpackOptions.output// both options are optionalfilename: "[name].css",chunkFilename: "[id].css",}),],module: {rules: [{test: /\.css$/,use: [{loader: MiniCssExtractPlugin.loader,options: {publicPath: (resourcePath,context)=>{returnpath.relative(path.dirname(resourcePath),context)+"/";},},},"css-loader",],},],},};

`emit`

Type: Boolean Default: true

If true, emits a file (writes a file to the filesystem). If false, the plugin will extract the CSS but will not emit the file. It is often useful to disable this option for server-side packages.

`esModule`

Type: Boolean Default: true

By default, mini-css-extract-plugin generates JS modules that use the ES modules syntax. There are some cases in which using ES modules is beneficial, like in the case of module concatenation and tree shaking.

You can enable a CommonJS syntax using:

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin()],module: {rules: [{test: /\.css$/i,use: [{loader: MiniCssExtractPlugin.loader,options: {esModule: false,},},"css-loader",],},],},};

Examples

Recommend

For production builds it's recommended to extract the CSS from your bundle being able to use parallel loading of CSS/JS resources later on. This can be achieved by using the mini-css-extract-plugin, because it creates separate css files. For development mode (including webpack-dev-server) you can use style-loader, because it injects CSS into the DOM using multiple <style></style> and works faster.

i Do not use together style-loader and mini-css-extract-plugin.

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");constdevMode=process.env.NODE_ENV!=="production";module.exports={module: {rules: [{test: /\.(sa|sc|c)ss$/,use: [devMode ? "style-loader" : MiniCssExtractPlugin.loader,"css-loader","postcss-loader","sass-loader",],},],},plugins: [].concat(devMode ? [] : [newMiniCssExtractPlugin()]),};

Minimal example

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({// Options similar to the same options in webpackOptions.output// all options are optionalfilename: "[name].css",chunkFilename: "[id].css",ignoreOrder: false,// Enable to remove warnings about conflicting order}),],module: {rules: [{test: /\.css$/,use: [{loader: MiniCssExtractPlugin.loader,options: {// you can specify a publicPath here// by default it uses publicPath in webpackOptions.outputpublicPath: "../",},},"css-loader",],},],},};

Named export for CSS Modules

⚠ Names of locals are converted to camelCase.

⚠ It is not allowed to use JavaScript reserved words in css class names.

⚠ Options esModule and modules.namedExport in css-loader should be enabled.

styles.css

.foo-baz {
color: red;
}
.bar {
color: blue;
}

index.js

import{fooBaz,bar}from"./styles.css";console.log(fooBaz,bar);

You can enable a ES module named export using:

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin()],module: {rules: [{test: /\.css$/,use: [{loader: MiniCssExtractPlugin.loader,},{loader: "css-loader",options: {esModule: true,modules: {namedExport: true,localIdentName: "foo__[name]__[local]",},},},],},],},};

The `publicPath` option as function

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({// Options similar to the same options in webpackOptions.output// both options are optionalfilename: "[name].css",chunkFilename: "[id].css",}),],module: {rules: [{test: /\.css$/,use: [{loader: MiniCssExtractPlugin.loader,options: {publicPath: (resourcePath,context)=>{// publicPath is the relative path of the resource to the context// e.g. for ./css/admin/main.css the publicPath will be ../../// while for ./css/main.css the publicPath will be ../returnpath.relative(path.dirname(resourcePath),context)+"/";},},},"css-loader",],},],},};

Advanced configuration example

This plugin should not be used with style-loader in the loaders chain.

Here is an example to have both HMR in development and your styles extracted in a file for production builds.

(Loaders options left out for clarity, adapt accordingly to your needs.)

You should not use HotModuleReplacementPlugin plugin if you are using a webpack-dev-server. webpack-dev-server enables / disables HMR using hot option.

webpack.config.js

constwebpack=require("webpack");constMiniCssExtractPlugin=require("mini-css-extract-plugin");constdevMode=process.env.NODE_ENV!=="production";constplugins=[newMiniCssExtractPlugin({// Options similar to the same options in webpackOptions.output// both options are optionalfilename: devMode ? "[name].css" : "[name].[contenthash].css",chunkFilename: devMode ? "[id].css" : "[id].[contenthash].css",}),];if(devMode){// only enable hot in developmentplugins.push(newwebpack.HotModuleReplacementPlugin());}module.exports={
plugins,module: {rules: [{test: /\.(sa|sc|c)ss$/,use: [MiniCssExtractPlugin.loader,"css-loader","postcss-loader","sass-loader",],},],},};

Hot Module Reloading (HMR)

Note: HMR is automatically supported in webpack 5. No need to configure it. Skip the following:

The mini-css-extract-plugin supports hot reloading of actual css files in development. Some options are provided to enable HMR of both standard stylesheets and locally scoped CSS or CSS modules. Below is an example configuration of mini-css for HMR use with CSS modules.

You should not use HotModuleReplacementPlugin plugin if you are using a webpack-dev-server. webpack-dev-server enables / disables HMR using hot option.

webpack.config.js

constwebpack=require("webpack");constMiniCssExtractPlugin=require("mini-css-extract-plugin");constplugins=[newMiniCssExtractPlugin({// Options similar to the same options in webpackOptions.output// both options are optionalfilename: devMode ? "[name].css" : "[name].[contenthash].css",chunkFilename: devMode ? "[id].css" : "[id].[contenthash].css",}),];if(devMode){// only enable hot in developmentplugins.push(newwebpack.HotModuleReplacementPlugin());}module.exports={
plugins,module: {rules: [{test: /\.css$/,use: [{loader: MiniCssExtractPlugin.loader,options: {},},"css-loader",],},],},};

Minimizing For Production

To minify the output, use a plugin like css-minimizer-webpack-plugin.

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");constCssMinimizerPlugin=require("css-minimizer-webpack-plugin");module.exports={plugins: [newMiniCssExtractPlugin({filename: "[name].css",chunkFilename: "[id].css",}),],module: {rules: [{test: /\.css$/,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},optimization: {minimizer: [// For webpack@5 you can use the `...` syntax to extend existing minimizers (i.e. `terser-webpack-plugin`), uncomment the next line// `...`,newCssMinimizerPlugin(),],},};

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

Using preloaded or inlined CSS

The runtime code detects already added CSS via <link> or <style> tag. This can be useful when injecting CSS on server-side for Server-Side-Rendering. The href of the <link> tag has to match the URL that will be used for loading the CSS chunk. The data-href attribute can be used for <link> and <style> too. When inlining CSS data-href must be used.

Extracting all CSS in a single file

The CSS can be extracted in one CSS file using optimization.splitChunks.cacheGroups.

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={optimization: {splitChunks: {cacheGroups: {styles: {name: "styles",type: "css/mini-extract",// For webpack@4// test: /\.css$/,chunks: "all",enforce: true,},},},},plugins: [newMiniCssExtractPlugin({filename: "[name].css",}),],module: {rules: [{test: /\.css$/,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

Note that type should be used instead of test in Webpack 5, or else an extra .js file can be generated besides the .css file. This is because test doesn't know which modules should be dropped (in this case, it won't detect that .js should be dropped).

Extracting CSS based on entry

You may also extract the CSS based on the webpack entry name. This is especially useful if you import routes dynamically but want to keep your CSS bundled according to entry. This also prevents the CSS duplication issue one had with the ExtractTextPlugin.

constpath=require("path");constMiniCssExtractPlugin=require("mini-css-extract-plugin");functionrecursiveIssuer(m,c){constissuer=c.moduleGraph.getIssuer(m);// For webpack@4 issuer = m.issuerif(issuer){returnrecursiveIssuer(issuer,c);}constchunks=c.chunkGraph.getModuleChunks(m);// For webpack@4 chunks = m._chunksfor(constchunkofchunks){returnchunk.name;}returnfalse;}module.exports={entry: {foo: path.resolve(__dirname,"src/foo"),bar: path.resolve(__dirname,"src/bar"),},optimization: {splitChunks: {cacheGroups: {fooStyles: {name: "styles_foo",test: (m,c,entry="foo")=>m.constructor.name==="CssModule"&&recursiveIssuer(m,c)===entry,chunks: "all",enforce: true,},barStyles: {name: "styles_bar",test: (m,c,entry="bar")=>m.constructor.name==="CssModule"&&recursiveIssuer(m,c)===entry,chunks: "all",enforce: true,},},},},plugins: [newMiniCssExtractPlugin({filename: "[name].css",}),],module: {rules: [{test: /\.css$/,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

Filename Option as function

With the filename option you can use chunk data to customize the filename. This is particularly useful when dealing with multiple entry points and wanting to get more control out of the filename for a given entry point/chunk. In the example below, we'll use filename to output the generated css into a different directory.

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({filename: ({ chunk })=>`${chunk.name.replace("/js/","/css/")}.css`,}),],module: {rules: [{test: /\.css$/,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

Long Term Caching

For long term caching use filename: "[contenthash].css". Optionally add [name].

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({filename: "[name].[contenthash].css",chunkFilename: "[id].[contenthash].css",}),],module: {rules: [{test: /\.css$/,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

Remove Order Warnings

For projects where css ordering has been mitigated through consistent use of scoping or naming conventions, the css order warnings can be disabled by setting the ignoreOrder flag to true for the plugin.

webpack.config.js

constMiniCssExtractPlugin=require("mini-css-extract-plugin");module.exports={plugins: [newMiniCssExtractPlugin({ignoreOrder: true,}),],module: {rules: [{test: /\.css$/i,use: [MiniCssExtractPlugin.loader,"css-loader"],},],},};

Media Query Plugin

If you'd like to extract the media queries from the extracted CSS (so mobile users don't need to load desktop or tablet specific CSS anymore) you should use one of the following plugins:

Contributing

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

CONTRIBUTING

License

MIT

Name		Name	Last commit message	Last commit date
.github		.github
.husky		.husky
src		src
test		test
.editorconfig		.editorconfig
.eslintignore		.eslintignore
.eslintrc.js		.eslintrc.js
.gitattributes		.gitattributes
.gitignore		.gitignore
.prettierignore		.prettierignore
CHANGELOG.md		CHANGELOG.md
LICENSE		LICENSE
README.md		README.md
babel.config.js		babel.config.js
commitlint.config.js		commitlint.config.js
jest.config.js		jest.config.js
lint-staged.config.js		lint-staged.config.js
package-lock.json		package-lock.json
package.json		package.json
setupTest.js		setupTest.js

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mini-css-extract-plugin

mini-css-extract-plugin

Getting Started

Options

Plugin Options

filename

chunkFilename

ignoreOrder

insert

String

Function

attributes

linkType

String

Boolean

skipRuntimeLoading

Boolean

experimentalUseImportModule

Loader Options

publicPath

String

Function

emit

esModule

Examples

Recommend

Minimal example

Named export for CSS Modules

The publicPath option as function

Advanced configuration example

Hot Module Reloading (HMR)

Minimizing For Production

Using preloaded or inlined CSS

Extracting all CSS in a single file

Extracting CSS based on entry

Filename Option as function

Long Term Caching

Remove Order Warnings

Media Query Plugin

Contributing

License

About

Resources

Contributing

Stars

Watchers

Forks

Releases

Packages

Contributors

Languages

`filename`

`chunkFilename`

`ignoreOrder`

`insert`

`String`

`Function`

`attributes`

`linkType`

`String`

`Boolean`

`skipRuntimeLoading`

`Boolean`

`experimentalUseImportModule`

`publicPath`

`String`

`Function`

`emit`

`esModule`

The `publicPath` option as function