PostCSS
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.
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 by plugins to do a lot of useful things, e.g., to find errors automatically, or to insert vendor prefixes.
Support / Discussion: Gitter
Twitter account: @postcss
VK.com page: postcss
中文翻译: docs/README-cn.md
For PostCSS commercial support (consulting, improving the front-end culture of your company, PostCSS plugins), contact Evil Martians at postcss@evilmartians.com.
Sponsorship
PostCSS needs your support. We are accepting donations at Open Collective.
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-preset-env
allows you to use future CSS features today.
Better CSS Readability
-
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.
Images and Fonts
-
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.
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
-
cssnano
is a modular CSS minifier. -
lost
is a feature-richcalc()
grid system. -
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-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-JS like 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 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
More articles and videos you can find on awesome-postcss list.
Books
- Mastering PostCSS for Web Design by Alex Libby, Packt. (June 2016)
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.
CSS-in-JS
The best way to use PostCSS with CSS-in-JS is astroturf
.
Add its loader to your webpack.config.js
:
module.exports = {
module: {
rules: [
{
test: /\.css$/,
use: ['style-loader', 'postcss-loader'],
},
{
test: /\.jsx?$/,
use: ['babel-loader', 'astroturf/loader'],
}
]
}
}
Then create postcss.config.js
:
/** @type {import('postcss-load-config').Config} */
const config = {
plugins: [
require('autoprefixer'),
require('postcss-nested')
]
}
module.exports = config
Parcel
Parcel has built-in PostCSS support. It already uses Autoprefixer
and cssnano. If you want to change plugins, create postcss.config.js
in project’s root:
/** @type {import('postcss-load-config').Config} */
const config = {
plugins: [
require('autoprefixer'),
require('postcss-nested')
]
}
module.exports = config
Parcel will even automatically install these plugins for you.
Please, be aware of the several issues in Version 1. Notice, Version 2 may resolve the issues via issue #2157.
Webpack
Use postcss-loader
in webpack.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 create postcss.config.js
:
/** @type {import('postcss-load-config').Config} */
const config = {
plugins: [
require('autoprefixer'),
require('postcss-nested')
]
}
module.exports = config
Gulp
Use gulp-postcss
and gulp-sourcemaps
.
gulp.task('css', () => {
const postcss = require('gulp-postcss')
const sourcemaps = require('gulp-sourcemaps')
return gulp.src('src/**/*.css')
.pipe( sourcemaps.init() )
.pipe( postcss([ require('autoprefixer'), require('postcss-nested') ]) )
.pipe( sourcemaps.write('.') )
.pipe( gulp.dest('build/') )
})
npm Scripts
To use PostCSS from your command-line interface or with npm scripts
there is postcss-cli
.
postcss --use autoprefixer -o main.css css/*.css
Browser
If you want to compile CSS string in browser (for instance, in live edit tools like CodePen), just use Browserify or webpack. They will pack PostCSS and plugins files into a single file.
To apply PostCSS plugins to React Inline Styles, JSS, Radium
and other CSS-in-JS, you can use postcss-js
and transforms style objects.
const postcss = require('postcss-js')
const prefixer = postcss.sync([ require('autoprefixer') ])
prefixer({ display: 'flex' }) //=> { display: ['-webkit-box', '-webkit-flex', '-ms-flexbox', 'flex'] }
Runners
-
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
JS API
For other environments, you can use the JS API:
const autoprefixer = require('autoprefixer')
const postcss = require('postcss')
const postcssNested = require('postcss-nested')
const fs = 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 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).
Treat Warnings as Errors
In some situations it might be helpful to fail the build on any warning
from PostCSS or one of its plugins. This guarantees that no warnings
go unnoticed, and helps to avoid bugs. While there is no option to enable
treating warnings as errors, it can easily be done
by adding postcss-fail-on-warn
plugin in the end of PostCSS plugins:
module.exports = {
plugins: [
require('autoprefixer'),
require('postcss-fail-on-warn')
]
}
Editors & IDE Integration
VS Code
-
csstools.postcss
adds PostCSS support.
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.
Vim
-
postcss.vim
adds PostCSS highlight.
WebStorm
To get support for PostCSS in WebStorm and other JetBrains IDEs you need to install this plugin.
Security Contact
To report a security vulnerability, please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.
For Enterprise
Available as part of the Tidelift Subscription.
The maintainers of postcss
and thousands of other packages are working
with Tidelift to deliver commercial support and maintenance for the open source
dependencies you use to build your applications. Save time, reduce risk,
and improve code health, while paying the maintainers of the exact dependencies
you use. Learn more.