Critters Webpack plugin

critters-webpack-plugin inlines your app's critical CSS and lazy-loads the rest.

critters-webpack-plugin

It's a little different from other options, because it doesn't use a headless browser to render content. This tradeoff allows Critters to be very fast and lightweight. It also means Critters inlines all CSS rules used by your document, rather than only those needed for above-the-fold content. For alternatives, see Similar Libraries.

Critters' design makes it a good fit when inlining critical CSS for prerendered/SSR'd Single Page Applications. It was developed to be an excellent compliment to prerender-loader, combining to dramatically improve first paint time for most Single Page Applications.

Features

Fast - no browser, few dependencies
Integrates with html-webpack-plugin
Works with webpack-dev-server / webpack serve
Supports preloading and/or inlining critical fonts
Prunes unused CSS keyframes and media queries
Removes inlined CSS rules from lazy-loaded stylesheets

Installation

First, install Critters as a development dependency:

npm i -D critters-webpack-plugin

Then, import Critters into your Webpack configuration and add it to your list of plugins:

// webpack.config.js
+const Critters = require('critters-webpack-plugin');

module.exports = {
  plugins: [
+    new Critters({
+      // optional configuration (see below)
+    })
  ]
}

That's it! Now when you run Webpack, the CSS used by your HTML will be inlined and the imports for your full CSS will be converted to load asynchronously.

Usage