purgecss

What is purgecss?

PurgeCSS is a tool to remove unused CSS. It can be used as part of your development workflow to reduce the size of your CSS files by removing unused selectors.

What are purgecss's main functionalities?

Basic Usage

This code demonstrates the basic usage of PurgeCSS. It scans HTML files and CSS files to remove unused CSS selectors.

const PurgeCSS = require('purgecss');
const purgeCSSResults = new PurgeCSS().purge({
  content: ['**/*.html'],
  css: ['**/*.css']
});
console.log(purgeCSSResults);

Using with PostCSS

This code shows how to integrate PurgeCSS with PostCSS. It processes CSS files and removes unused selectors based on the content of HTML files.

const postcss = require('postcss');
const purgecss = require('@fullhuman/postcss-purgecss');

postcss([
  purgecss({
    content: ['./src/**/*.html']
  })
]).process(css, { from: 'src/app.css', to: 'dist/app.css' })
  .then(result => {
    console.log(result.css);
  });

Using with Webpack

This code demonstrates how to use PurgeCSS as a Webpack plugin. It scans the specified paths for content and removes unused CSS selectors during the Webpack build process.

const PurgeCSSPlugin = require('purgecss-webpack-plugin');
const glob = require('glob');
const path = require('path');

module.exports = {
  // other webpack config
  plugins: [
    new PurgeCSSPlugin({
      paths: glob.sync(`${path.join(__dirname, 'src')}/**/*`, { nodir: true }),
    }),
  ],
};

Other packages similar to purgecss

uncss

UnCSS is a tool that removes unused CSS from your stylesheets. It works similarly to PurgeCSS by scanning your HTML files to determine which CSS selectors are not used. However, UnCSS is generally considered to be less flexible and slower compared to PurgeCSS.

purify-css

PurifyCSS is another tool for removing unused CSS. It scans your HTML and JavaScript files to find which CSS selectors are used. While it is similar to PurgeCSS, it is not as actively maintained and may lack some of the advanced features and integrations that PurgeCSS offers.

csso

CSSO (CSS Optimizer) is a CSS minifier that also has the capability to remove unused CSS. It is primarily focused on minification and optimization, but it can also be used to remove unused CSS selectors. CSSO is generally faster but may not be as thorough in removing unused CSS as PurgeCSS.

README

Purgecss

What is purgecss?

When you are building a website, chances are that you are using a css framework like Bootstrap, Materializecss, Foundation, etc... But you will only use a small set of the framework and a lot of unused css styles will be included.

This is where Purgecss comes into play. Purgecss analyzes your content and your css files. Then it matches the selectors used in your files with the one in your content files. It removes unused selectors from your css, resulting in smaller css files.

Documentation

You can find the purgecss documentation on this website.

• Configuration
• CLI
• Javascript API
• Webpack plugin
• Gulp plugin
• Rollup plugin
• Whitelisting
• Extractors
• Comparison

Getting Started

Installation

npm i --save-dev purgecss

Usage

import Purgecss from 'purgecss'
const purgeCss = new Purgecss({
  content: ['**/*.html'],
  css: ['**/*.css']
})
const result = purgecss.purge()

With a custom extractor:

import Purgecss from 'purgecss'
import purgeHtml from 'purgecss-from-html'
const purgeCss = new Purgecss({
  content: ['**/*.html'],
  css: ['**/*.css'],
  extractors: [
    {
      extractor: purgeHtml,
      extensions: ['html']
    }
  ]
})
const result = purgecss.purge()

Build Plugin

• Webpack
• Gulp
• Rollup

Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

Versioning

Purgecss use SemVer for versioning.

Acknowledgment

Purgecss was originally thought as the v2 of purifycss. And because of it, it is greatly inspired by it.
Some of the plugins such as purgecss-webpack-plugin are based on the purifycss plugin.
Below is the list of the purifycss repositories:

• purifycss
• gulp-purifycss
• purifycss-webpack

License

This project is licensed under the MIT License - see the LICENSE file for details.

Troubleshooting

Wrong extractor is selected

The extractors needs to be defined from the more specific to the less specific. Meaning that you need to define js extractor after ejs. So the js extractor will not be selected for ejs files.

You can specified extensions like .es.js.

Changelog

0.20.0 (2018-01-30)

• https://github.com/FullHuman/purgecss/pull/48, fix https://github.com/FullHuman/purgecss/issues/41
• New option fontFace to remove unused font-face declaration
• Remove unused vendor-prefixed keyframes rules
• Update dependencies