addyosmani/critical

Health v2 · maintenance only

Adoption not part of the score

10265 stars · 389 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

A Node.js tool that extracts above-the-fold (critical-path) CSS from HTML pages, inlines it into the document head, and asynchronously loads the remaining stylesheets to eliminate render-blocking CSS. It offers both a CLI and a JavaScript API, with two extraction engines (DOM-based and browser-rendered) and an MCP server for coding agents.

Use cases

• extract critical css from html
• inline above-the-fold css to improve first paint
• remove render-blocking stylesheets
• improve largest contentful paint score
• optimize css for static site builds
• defer non-critical css loading
• generate critical css in ci pipeline

When to choose

• you need faster first paint and better LCP on static sites, MPAs, or SPAs
• you want deterministic output safe for CI and version control diffs
• you need a tool that works under strict Content Security Policy without inline scripts
• you want both a CLI for build pipelines and an API for programmatic use

When to avoid

• your pages have no external stylesheets or already inline all CSS
• you need full CSS optimization like minification or purging unused styles across the whole page
• you cannot run Node.js in your build environment

Facets

cli-tool · maturity active

css-framework build-tool cli developer-tools web-development frontend performance web-design cli critical-css above-the-fold render-blocking web-performance lcp-optimization css-inlining mcp-server nodejs web-server

Member repositories

For agents

markdown · JSON · MCP: product_card(name="addyosmani/critical")