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PostCSS is a tool for transforming styles with JS plugins.These plugins can lint your CSS, support variables and mixins,transpile future CSS syntax, inline images, and more.

PostCSS is used by industry leaders including Wikipedia, Twitter, Alibaba,and JetBrains. The Autoprefixer andStylelint PostCSS plugins is one of the most popular CSS tools.

  Made atEvil Martians, product consulting fordeveloper tools.

PostCSS needs your support. We are accepting donationsat Open Collective.

PostCSS takes a CSS file and provides an API to analyze and modify its rules(by transforming them into an Abstract Syntax Tree).This API can then be used byplugins to do a lot of useful things,e.g., to find errors automatically, or to insert vendor prefixes.

Currently, PostCSS has more than 200 plugins. You can find all of the pluginsin theplugins list. Below is a list of our favorite plugins —the best demonstrations of what can be built on top of PostCSS.

If you have any new ideas,PostCSS plugin development is really easy.

• postcss-use allows you to explicitly set PostCSS plugins within CSSand execute them only for the current file.
• postcss-modules andreact-css-modules automatically isolateselectors within components.
• postcss-autoreset is an alternative to using a global resetthat is better for isolatable components.
• postcss-initial addsall: initial support, which resetsall inherited styles.
• cq-prolyfill adds container query support, allowing styles that respondto the width of the parent.

• autoprefixer adds vendor prefixes, using data from Can I Use.
• postcss-preset-env allows you to use future CSS features today.

• postcss-nested unwraps nested rules the way Sass does.
• postcss-sorting sorts the content of rules and at-rules.
• postcss-utilities includes the most commonly used shortcuts and helpers.
• short adds and extends numerous shorthand properties.

• postcss-url postcss plugin to rebase url(), inline or copy asset.
• postcss-sprites generates image sprites.
• font-magician generates all the@font-face rules needed in CSS.
• postcss-inline-svg allows you to inline SVG and customize its styles.
• postcss-write-svg allows you to write simple SVG directly in your CSS.
• webp-in-css to use WebP image format in CSS background.
• avif-in-css to use AVIF image format in CSS background.

• stylelint is a modular stylesheet linter.
• stylefmt is a tool that automatically formats CSSaccordingstylelint rules.
• doiuse lints CSS for browser support, using data from Can I Use.
• colorguard helps you maintain a consistent color palette.

• cssnano is a modular CSS minifier.
• lost is a feature-richcalc() grid system.
• rtlcss mirrors styles for right-to-left locales.

PostCSS can transform styles in any syntax, not just CSS.If there is not yet support for your favorite syntax,you can write a parser and/or stringifier to extend PostCSS.

• sugarss is a indent-based syntax like Sass or Stylus.
• postcss-syntax switch syntax automatically by file extensions.
• postcss-html parsing styles in<style> tags of HTML-like files.
• postcss-markdown parsing styles in code blocks of Markdown files.
• postcss-styled-syntax parses styles in template literals CSS-in-JSlike styled-components.
• postcss-jsx parsing CSS in template / object literals of source files.
• postcss-styled parsing CSS in template literals of source files.
• postcss-scss allows you to work with SCSS(but does not compile SCSS to CSS).
• postcss-sass allows you to work with Sass(but does not compile Sass to CSS).
• postcss-less allows you to work with Less(but does not compile LESS to CSS).
• postcss-less-engine allows you to work with Less(and DOES compile LESS to CSS using true Less.js evaluation).
• postcss-js allows you to write styles in JS or transformReact Inline Styles, Radium or JSS.
• postcss-safe-parser finds and fixes CSS syntax errors.
• midas converts a CSS string to highlighted HTML.

• Some things you may think about PostCSS… and you might be wrong
• What PostCSS Really Is; What It Really Does
• PostCSS Guides

More articles and videos you can find onawesome-postcss list.

• Mastering PostCSS for Web Design by Alex Libby, Packt. (June 2016)

You can start using PostCSS in just two steps:

1. Find and add PostCSS extensions for your build tool.
2. Select plugins and add them to your PostCSS process.

The best way to use PostCSS with CSS-in-JS isastroturf.Add its loader to yourwebpack.config.js:

module.exports={module:{rules:[{test:/\.css$/,use:['style-loader','postcss-loader'],},{test:/\.jsx?$/,use:['babel-loader','astroturf/loader'],}]}}

Then createpostcss.config.js:

/**@type {import('postcss-load-config').Config} */constconfig={plugins:[require('autoprefixer'),require('postcss-nested')]}module.exports=config

Parcel has built-in PostCSS support. It already uses Autoprefixerand cssnano. If you want to change plugins, createpostcss.config.jsin project’s root:

/**@type {import('postcss-load-config').Config} */constconfig={plugins:[require('autoprefixer'),require('postcss-nested')]}module.exports=config

Parcel will even automatically install these plugins for you.

Please, be aware ofthe several issues in Version 1. Notice,Version 2 may resolve the issues viaissue #2157.

Usepostcss-loader inwebpack.config.js:

module.exports={module:{rules:[{test:/\.css$/,exclude:/node_modules/,use:[{loader:'style-loader',},{loader:'css-loader',options:{importLoaders:1,}},{loader:'postcss-loader'}]}]}}

Then createpostcss.config.js:

/**@type {import('postcss-load-config').Config} */constconfig={plugins:[require('autoprefixer'),require('postcss-nested')]}module.exports=config

Usegulp-postcss andgulp-sourcemaps.

gulp.task('css',()=>{constpostcss=require('gulp-postcss')constsourcemaps=require('gulp-sourcemaps')returngulp.src('src/**/*.css').pipe(sourcemaps.init()).pipe(postcss([require('autoprefixer'),require('postcss-nested')])).pipe(sourcemaps.write('.')).pipe(gulp.dest('build/'))})

To use PostCSS from your command-line interface or with npm scriptsthere ispostcss-cli.

postcss --use autoprefixer -o main.css css/*.css

If you want to compile CSS string in browser (for instance, in live edittools like CodePen), just useBrowserify orwebpack. They will packPostCSS and plugins files into a single file.

To apply PostCSS plugins to React Inline Styles, JSS, Radiumand otherCSS-in-JS, you can usepostcss-js and transforms style objects.

constpostcss=require('postcss-js')constprefixer=postcss.sync([require('autoprefixer')])prefixer({display:'flex'})//=> { display: ['-webkit-box', '-webkit-flex', '-ms-flexbox', 'flex'] }

• Grunt:@lodder/grunt-postcss
• HTML:posthtml-postcss
• Stylus:poststylus
• Rollup:rollup-plugin-postcss
• Brunch:postcss-brunch
• Broccoli:broccoli-postcss
• Meteor:postcss
• ENB:enb-postcss
• Taskr:taskr-postcss
• Start:start-postcss
• Connect/Express:postcss-middleware
• Svelte Preprocessor:svelte-preprocess

For other environments, you can use the JS API:

constautoprefixer=require('autoprefixer')constpostcss=require('postcss')constpostcssNested=require('postcss-nested')constfs=require('fs')fs.readFile('src/app.css',(err,css)=>{postcss([autoprefixer,postcssNested]).process(css,{from:'src/app.css',to:'dest/app.css'}).then(result=>{fs.writeFile('dest/app.css',result.css,()=>true)if(result.map){fs.writeFile('dest/app.css.map',result.map.toString(),()=>true)}})})

Read thePostCSS API documentation for more details about the JS API.

All PostCSS runners should passPostCSS Runner Guidelines.

Most PostCSS runners accept two parameters:

• An array of plugins.
• An object of options.

Common options:

• syntax: an object providing a syntax parser and a stringifier.
• parser: a special syntax parser (for example,SCSS).
• stringifier: a special syntax output generator (for example,Midas).
• map:source map options.
• from: the input file name (most runners set it automatically).
• to: the output file name (most runners set it automatically).

In some situations it might be helpful to fail the build on any warningfrom PostCSS or one of its plugins. This guarantees that no warningsgo unnoticed, and helps to avoid bugs. While there is no option to enabletreating warnings as errors, it can easily be doneby addingpostcss-fail-on-warn plugin in the end of PostCSS plugins:

module.exports={plugins:[require('autoprefixer'),require('postcss-fail-on-warn')]}

• csstools.postcss adds PostCSS support.

• Syntax-highlighting-for-PostCSS adds PostCSS highlight.

• postcss.vim adds PostCSS highlight.

To get support for PostCSS in WebStorm and other JetBrains IDEs you need to installthis plugin.

To report a security vulnerability, please use theTidelift security contact.Tidelift will coordinate the fix and disclosure.

Available as part of the Tidelift Subscription.

The maintainers ofpostcss and thousands of other packages are workingwith Tidelift to deliver commercial support and maintenance for the open sourcedependencies you use to build your applications. Save time, reduce risk,and improve code health, while paying the maintainers of the exact dependenciesyou use.Learn more.