Core Web Vitals in 2026: The Practical Fixes for INP, LCP, and CLS That Actually Work Your Lighthouse score says 95. Your users say your site feels slow. Here's why — and exactly how to fix each metric with code you can ship today. Why Your Lighthouse Score Is Lying to You There's a hard truth most teams learn the painful way: the number in your terminal is not the number Google cares about. Lighthouse runs in a simulated environment — a powerful desktop with a fast connection. Google's ranking signal comes from CrUX (Chrome User Experience Report), which measures real users on real devices on real networks . It looks at the 75th percentile over a rolling 28-day window. Your Lighthouse run is a lab test. CrUX is the field result. I've seen teams spend weeks polishing a 98 Lighthouse score while their actual INP — the metric that measures how responsive your site feels — sat firmly in the "poor" bucket for every mobile user. The gap between lab and field can be enormous.…