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mini-css-extract-plugin
Advanced tools
The mini-css-extract-plugin is a plugin for webpack that 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 requires webpack 4 to function.
Extract CSS into separate files
This feature allows you to extract CSS from your bundle into a separate file, which can be loaded independently.
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
module: {
rules: [
{
test: /\.css$/,
use: [
MiniCssExtractPlugin.loader,
'css-loader'
]
}
]
},
plugins: [
new MiniCssExtractPlugin({
filename: '[name].css',
chunkFilename: '[id].css'
})
]
};
Lazy loading of CSS files
This feature enables on-demand loading of CSS by splitting the CSS into chunks and loading them when needed.
import(/* webpackChunkName: 'style' */ './style.css').then(() => {
// Use style.css
});
SourceMap support
This feature allows you to generate source maps for the CSS files, which is helpful for debugging purposes.
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
module: {
rules: [
{
test: /\.css$/,
use: [
{
loader: MiniCssExtractPlugin.loader,
options: {
sourceMap: true
}
},
{
loader: 'css-loader',
options: {
sourceMap: true
}
}
]
}
]
},
plugins: [
new MiniCssExtractPlugin({
filename: '[name].css',
chunkFilename: '[id].css'
})
]
};
This package is similar to mini-css-extract-plugin but was used for webpack 3 and earlier. It is now deprecated in favor of mini-css-extract-plugin, which is designed for webpack 4 and later.
This package injects CSS into the DOM using multiple <style> tags. It is often used in development environments for hot module replacement but does not extract CSS into separate files.
While sass-loader itself does not extract CSS, it is commonly used in conjunction with mini-css-extract-plugin to compile Sass/SCSS files into CSS and then extract it into separate files.
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 v4 feature (module types) and requires webpack 4 to work.
Compared to the extract-text-webpack-plugin:
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
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [new MiniCssExtractPlugin()],
module: {
rules: [
{
test: /\.css$/i,
use: [MiniCssExtractPlugin.loader, 'css-loader'],
},
],
},
};
publicPath
Type: String|Function
Default: the publicPath
in webpackOptions.output
Specifies a custom public path for the target file(s).
String
webpack.config.js
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [
new MiniCssExtractPlugin({
// Options similar to the same options in webpackOptions.output
// both options are optional
filename: '[name].css',
chunkFilename: '[id].css',
}),
],
module: {
rules: [
{
test: /\.css$/,
use: [
{
loader: MiniCssExtractPlugin.loader,
options: {
publicPath: '/public/path/to/',
},
},
'css-loader',
],
},
],
},
};
Function
webpack.config.js
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [
new MiniCssExtractPlugin({
// Options similar to the same options in webpackOptions.output
// both options are optional
filename: '[name].css',
chunkFilename: '[id].css',
}),
],
module: {
rules: [
{
test: /\.css$/,
use: [
{
loader: MiniCssExtractPlugin.loader,
options: {
publicPath: (resourcePath, context) => {
return path.relative(path.dirname(resourcePath), context) + '/';
},
},
},
'css-loader',
],
},
],
},
};
esModule
Type: Boolean
Default: false
By default, mini-css-extract-plugin
generates JS modules that use the CommonJS modules syntax.
There are some cases in which using ES modules is beneficial, like in the case of module concatenation and tree shaking.
You can enable a ES module syntax using:
webpack.config.js
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [new MiniCssExtractPlugin()],
module: {
rules: [
{
test: /\.css$/i,
use: [
{
loader: MiniCssExtractPlugin.loader,
options: {
esModule: true,
},
},
'css-loader',
],
},
],
},
};
modules
Type: Object
Default: undefined
Configuration CSS Modules.
namedExport
Type: Boolean
Default: false
Enables/disables ES modules named export for locals.
⚠ Names of locals are converted to
camelCase
.
⚠ It is not allowed to use JavaScript reserved words in css class names.
⚠ Options
esModule
andmodules.namedExport
incss-loader
andMiniCssExtractPlugin.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
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [new MiniCssExtractPlugin()],
module: {
rules: [
{
test: /\.css$/,
use: [
{
loader: MiniCssExtractPlugin.loader,
options: {
esModule: true,
modules: {
namedExport: true,
},
},
},
{
loader: 'css-loader',
options: {
esModule: true,
modules: {
namedExport: true,
localIdentName: 'foo__[name]__[local]',
},
},
},
],
},
],
},
};
webpack.config.js
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [
new MiniCssExtractPlugin({
// Options similar to the same options in webpackOptions.output
// all options are optional
filename: '[name].css',
chunkFilename: '[id].css',
ignoreOrder: false, // Enable to remove warnings about conflicting order
}),
],
module: {
rules: [
{
test: /\.css$/,
use: [
{
loader: MiniCssExtractPlugin.loader,
options: {
// you can specify a publicPath here
// by default it uses publicPath in webpackOptions.output
publicPath: '../',
hmr: process.env.NODE_ENV === 'development', // webpack 4 only
},
},
'css-loader',
],
},
],
},
};
publicPath
option as functionwebpack.config.js
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [
new MiniCssExtractPlugin({
// Options similar to the same options in webpackOptions.output
// both options are optional
filename: '[name].css',
chunkFilename: '[id].css',
}),
],
module: {
rules: [
{
test: /\.css$/,
use: [
{
loader: MiniCssExtractPlugin.loader,
options: {
publicPath: (resourcePath, context) => {
// publicPath is the relative path of the resource to the context
// e.g. for ./css/admin/main.css the publicPath will be ../../
// while for ./css/main.css the publicPath will be ../
return path.relative(path.dirname(resourcePath), context) + '/';
},
},
},
'css-loader',
],
},
],
},
};
This plugin should be used only on production
builds without style-loader
in the loaders chain, especially if you want to have HMR in development
.
Here is an example to have both HMR in development
and your styles extracted in a file for production
builds.
(Loaders options left out for clarity, adapt accordingly to your needs.)
webpack.config.js
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const devMode = process.env.NODE_ENV !== 'production';
module.exports = {
plugins: [
new MiniCssExtractPlugin({
// Options similar to the same options in webpackOptions.output
// both options are optional
filename: devMode ? '[name].css' : '[name].[hash].css',
chunkFilename: devMode ? '[id].css' : '[id].[hash].css',
}),
],
module: {
rules: [
{
test: /\.(sa|sc|c)ss$/,
use: [
{
loader: MiniCssExtractPlugin.loader,
options: {
hmr: process.env.NODE_ENV === 'development', // webpack 4 only
},
},
'css-loader',
'postcss-loader',
'sass-loader',
],
},
],
},
};
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.
While we attempt to hmr css-modules. It is not easy to perform when code-splitting with custom chunk names.
reloadAll
is an option that should only be enabled if HMR isn't working correctly.
The core challenge with css-modules is that when code-split, the chunk ids can and do end up different compared to the filename.
webpack.config.js
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [
new MiniCssExtractPlugin({
// Options similar to the same options in webpackOptions.output
// both options are optional
filename: '[name].css',
chunkFilename: '[id].css',
}),
],
module: {
rules: [
{
test: /\.css$/,
use: [
{
loader: MiniCssExtractPlugin.loader,
options: {
// only enable hot in development (webpack 4 only)
hmr: process.env.NODE_ENV === 'development',
// if hmr does not work, this is a forceful method.
reloadAll: true,
},
},
'css-loader',
],
},
],
},
};
To minify the output, use a plugin like optimize-css-assets-webpack-plugin.
Setting optimization.minimizer
overrides the defaults provided by webpack, so make sure to also specify a JS minimizer:
webpack.config.js
const TerserJSPlugin = require('terser-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
module.exports = {
optimization: {
minimizer: [new TerserJSPlugin({}), new OptimizeCSSAssetsPlugin({})],
},
plugins: [
new MiniCssExtractPlugin({
filename: '[name].css',
chunkFilename: '[id].css',
}),
],
module: {
rules: [
{
test: /\.css$/,
use: [MiniCssExtractPlugin.loader, 'css-loader'],
},
],
},
};
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.
The CSS can be extracted in one CSS file using optimization.splitChunks.cacheGroups
.
webpack.config.js
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
optimization: {
splitChunks: {
cacheGroups: {
styles: {
name: 'styles',
test: /\.css$/,
chunks: 'all',
enforce: true,
},
},
},
},
plugins: [
new MiniCssExtractPlugin({
filename: '[name].css',
}),
],
module: {
rules: [
{
test: /\.css$/,
use: [MiniCssExtractPlugin.loader, 'css-loader'],
},
],
},
};
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.
const path = require('path');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
function recursiveIssuer(m) {
if (m.issuer) {
return recursiveIssuer(m.issuer);
} else if (m.name) {
return m.name;
} else {
return false;
}
}
module.exports = {
entry: {
foo: path.resolve(__dirname, 'src/foo'),
bar: path.resolve(__dirname, 'src/bar'),
},
optimization: {
splitChunks: {
cacheGroups: {
fooStyles: {
name: 'foo',
test: (m, c, entry = 'foo') =>
m.constructor.name === 'CssModule' && recursiveIssuer(m) === entry,
chunks: 'all',
enforce: true,
},
barStyles: {
name: 'bar',
test: (m, c, entry = 'bar') =>
m.constructor.name === 'CssModule' && recursiveIssuer(m) === entry,
chunks: 'all',
enforce: true,
},
},
},
},
plugins: [
new MiniCssExtractPlugin({
filename: '[name].css',
}),
],
module: {
rules: [
{
test: /\.css$/,
use: [MiniCssExtractPlugin.loader, 'css-loader'],
},
],
},
};
With the moduleFilename
option you can use chunk data to customize the filename. This is particularly useful when dealing with multiple entry points and wanting to get more control out of the filename for a given entry point/chunk. In the example below, we'll use moduleFilename
to output the generated css into a different directory.
webpack.config.js
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [
new MiniCssExtractPlugin({
moduleFilename: ({ name }) => `${name.replace('/js/', '/css/')}.css`,
}),
],
module: {
rules: [
{
test: /\.css$/,
use: [MiniCssExtractPlugin.loader, 'css-loader'],
},
],
},
};
For long term caching use filename: "[contenthash].css"
. Optionally add [name]
.
webpack.config.js
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [
new MiniCssExtractPlugin({
filename: '[name].[contenthash].css',
chunkFilename: '[id].[contenthash].css',
}),
],
module: {
rules: [
{
test: /\.css$/,
use: [MiniCssExtractPlugin.loader, 'css-loader'],
},
],
},
};
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
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module.exports = {
plugins: [
new MiniCssExtractPlugin({
ignoreOrder: true,
}),
],
module: {
rules: [
{
test: /\.css$/i,
use: [MiniCssExtractPlugin.loader, 'css-loader'],
},
],
},
};
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:
Please take a moment to read our contributing guidelines if you haven't yet done so.
FAQs
extracts CSS into separate files
The npm package mini-css-extract-plugin receives a total of 12,284,769 weekly downloads. As such, mini-css-extract-plugin popularity was classified as popular.
We found that mini-css-extract-plugin demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 3 open source maintainers collaborating on the project.
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