Definition
Google Lighthouse is an open-source audit tool developed by Google, integrated into Chrome DevTools and available as a command-line tool. It automatically analyzes a web page and generates detailed reports in five categories: Performance (Core Web Vitals, loading times), Accessibility (WCAG compliance), Best Practices (security, modern APIs), SEO (meta tags, indexability, structured data), and Progressive Web App. Each category receives a 0-100 score with actionable recommendations. Lighthouse has become essential in technical SEO because it measures Core Web Vitals (LCP, INP, CLS) which are Google ranking factors.
Key Points
- Open-source Google tool integrated into Chrome DevTools for page auditing
- Evaluates Performance, Accessibility, SEO, Best Practices, and PWA
- Measures Core Web Vitals (LCP, INP, CLS) that influence Google ranking
Practical Examples
Technical SEO audit
Run Lighthouse on your homepage via Chrome DevTools (F12 > Lighthouse tab) for a complete diagnostic: performance score, accessibility issues, SEO errors, and optimization recommendations.
CI/CD integration
Integrate Lighthouse into your CI/CD pipeline with lighthouse-ci to automate performance audits on each deployment and prevent Core Web Vitals regressions.
Frequently Asked Questions
PageSpeed Insights uses Lighthouse as its backend but adds field data (CrUX) from real users. Lighthouse provides a lab audit, while PSI combines lab and field data for a more complete diagnostic.
No, a perfect score is not necessary and is often difficult to achieve. Aim for 90+ for Performance and SEO. The important thing is to fix critical issues and progressively improve key metrics.
Go Further with LemmiLink
Discover how LemmiLink can help you put these SEO concepts into practice.
Last updated: 2026-02-07