A Lighthouse score is a performance rating, from 0 to 100, generated by Google’s open-source Lighthouse auditing tool, evaluating a webpage across performance, accessibility, best practices, and SEO categories through a simulated (lab-based) test.
Lighthouse powers the performance testing behind several other tools, including PageSpeed Insights, and can also be run directly within Chrome’s own developer tools for quick, on-demand performance checks during development.
Because Lighthouse scores are based on simulated lab conditions rather than real user data, they should be interpreted alongside actual field data (like Core Web Vitals reports) for a complete, accurate performance picture.
We use Lighthouse audits within our Technical SEO service.