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 PostCSS plugin is one of the most popular CSS processors.
Twitter account: @postcss. VK.com page: postcss. Support / Discussion: Gitter.
Plugins
Currently, PostCSS has more than 200 plugins. You can find all of the plugins in the plugins list or in the searchable catalog. 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.
Solve Global CSS Problem
postcss-use
allows you to explicitly set PostCSS plugins within CSS and execute them only for the current file.postcss-modules
andreact-css-modules
automatically isolate selectors within components.postcss-autoreset
is an alternative to using a global reset that is better for isolatable components.postcss-initial
addsall: initial
support, which resets all inherited styles.cq-prolyfill
adds container query support, allowing styles that respond to the width of the parent.
Use Future CSS, Today
autoprefixer
adds vendor prefixes, using data from Can I Use.postcss-cssnext
allows you to use future CSS features today (includesautoprefixer
).
Better CSS Readability
precss
contains plugins for Sass-like features, like variables, nesting, and mixins.postcss-sorting
sorts the content of rules and at-rules.short
adds and extends numerous shorthand properties.
Images and Fonts
postcss-assets
inserts image dimensions and inlines files.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.
Linters
stylelint
is a modular stylesheet linter.stylefmt
is a tool that automatically formats CSS accordingstylelint
rules.doiuse
lints CSS for browser support, using data from Can I Use.colorguard
helps you maintain a consistent color palette.
Other
lost
is a feature-richcalc()
grid system.cssnano
is a modular CSS minifier.rtlcss
mirrors styles for right-to-left locales.
Syntaxes
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-scss
allows you to work with SCSS (but does not compile SCSS 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 transform React Inline Styles, Radium or JSS.postcss-safe-parser
finds and fixes CSS syntax errors.midas
converts a CSS string to highlighted HTML.
Articles
- Some things you may think about PostCSS… and you might be wrong
- What PostCSS Really Is; What It Really Does
- PostCSS Guides
Usage
You can start using PostCSS in just two steps:
- Find and add PostCSS extensions for your build tool.
- Select plugins and add them to your PostCSS process.
Gulp
Use gulp-postcss
and gulp-sourcemaps
.
gulp.task('css', function () {
var postcss = require('gulp-postcss');
var sourcemaps = require('gulp-sourcemaps');
return gulp.src('src/**/*.css')
.pipe( sourcemaps.init() )
.pipe( postcss([ require('autoprefixer'), require('precss') ]) )
.pipe( sourcemaps.write('.') )
.pipe( gulp.dest('build/') );
});
Webpack
Use postcss-loader
:
module.exports = {
module: {
loaders: [
{
test: /\.css$/,
loader: "style-loader!css-loader!postcss-loader"
}
]
},
postcss: function () {
return [require('autoprefixer'), require('precss')];
}
}
npm run / CLI
To use PostCSS from your command-line interface or with npm scripts
there is postcss-cli
.
postcss --use autoprefixer -c options.json -o main.css css/*.css
CSS-in-JS
To apply PostCSS plugins to React Inline Styles, JSS, Radium
and other CSS-in-JS, you can use postcss-js
and transforms style objects.
var postcss = require('postcss-js');
var prefixer = postcss.sync([ require('autoprefixer') ]);
prefixer({ display: 'flex' }); //=> { display: ['-webkit-box', '-webkit-flex', '-ms-flexbox', 'flex'] }
Runners
- Grunt:
grunt-postcss
- HTML:
posthtml-postcss
- Stylus:
poststylus
- Rollup:
rollup-plugin-postcss
- Brunch:
postcss-brunch
- Broccoli:
broccoli-postcss
- Meteor:
postcss
- ENB:
enb-postcss
- Fly:
fly-postcss
- Start:
start-postcss
- Connect/Express:
postcss-middleware
JS API
For other environments, you can use the JS API:
var postcss = require('postcss');
postcss([ require('autoprefixer'), require('cssnano') ])
.process(css, { from: 'src/app.css', to: 'app.css' })
.then(function (result) {
fs.writeFileSync('app.css', result.css);
if ( result.map ) fs.writeFileSync('app.css.map', result.map);
});
Read the PostCSS API documentation for more details about the JS API.
All PostCSS runners should pass PostCSS Runner Guidelines.
Options
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).
Node.js 0.10 and the Promise API
If you want to run PostCSS in Node.js 0.10, add the Promise polyfill:
require('es6-promise').polyfill();
var postcss = require('postcss');
IDE Integration
Atom
language-postcss
adds PostCSS and [SugarSS] highlight.source-preview-postcss
previews your output CSS in a separate, live pane.
Sublime Text
Syntax-highlighting-for-PostCSS
adds PostCSS highlight.
WebStorm
Support is still in progress. Please support WEB-16601 issue in JetBrains tracker.