Learn Google Lighthouse
Guides and tutorials for improving your site's Core Web Vitals and performance. All guides include authoritative citations from Google and real-world statistics.
Core Web Vitals
Core Web Vitals are Google's ranking factor for measuring user experience. Only 48% of mobile sites currently pass all three metrics.
59%
mobile pass rate
Largest Contentful Paint (LCP)
Improve loading performance. Only 59% of mobile sites pass.
79%
mobile pass rate
Cumulative Layout Shift (CLS)
Eliminate layout shifts. 79% of mobile sites pass.
New
replaced FID
Interaction to Next Paint (INP)
Make interactions responsive. Replaced FID in March 2024.
Guides
Core Web Vitals Overview
What they measure, why they matter, and how to test them.
Bulk Lighthouse Testing
Test every page, not just the homepage.
Lighthouse CI
Automate audits in your CI/CD pipeline with @lhci/cli.
PageSpeed Insights API
Fetch Lighthouse data programmatically with Node.js or Python.
PSI vs Lighthouse
Why scores differ between PageSpeed Insights and local Lighthouse.
Lighthouse with Playwright
Run audits on authenticated pages and SPAs.
Audit Categories
Free Tools
Test Your Entire Site
Most tools only test one page at a time. Unlighthouse scans your entire site and shows scores for every page.