Internet
Aug 7, 2026
Your Lighthouse Score Is 95 and Your Users Still Complain the Site Is Slow — Lab Data, Field Data, and Why They Diverge
A Lighthouse score of 95 and a poor real-user experience aren't contradictory — Lighthouse simulates a clean browser state on standardised throttled conditions, while CrUX captures real users with extensions, background tabs, budget Android devices, and variable networks. Here's why INP (which replaced FID in March 2024) is now the most-failed Core Web Vital on JavaScript-heavy apps, how CDN geographic coverage creates lab vs field score divergence, and why the LCP image needs fetchpriority="high" to download as early as possible.