What is a Google PageSpeed score and does it affect my ranking?

A Google PageSpeed Insights score is a 0–100 lab estimate of how fast a page loads and becomes usable, produced by Google’s Lighthouse engine for mobile and desktop separately:

• 90+ — rated good
• 50–89 — needs improvement
• below 50 — poor

It affects ranking only indirectly: Google’s ranking systems use Core Web Vitals measured from real visitors (the field data shown at the top of the report when available), not the lab score itself, and page experience is a lightweight signal compared with content relevance. The practical reason to care is customers, not Google — a page that takes 6 seconds to load on a phone loses people long before it loses rankings. Mobile score is the one to watch.