The thresholds
Google publishes these thresholds, measured at the 75th percentile of real visits (so three in four visits need to meet them):
| Metric | Good | Needs improvement | Poor |
|---|---|---|---|
| LCP: loading | ≤ 2.5 s | 2.5–4.0 s | > 4.0 s |
| INP: responsiveness | ≤ 200 ms | 200–500 ms | > 500 ms |
| CLS: visual stability | ≤ 0.1 | 0.1–0.25 | > 0.25 |
A page “passes” Core Web Vitals when all three are good. Thresholds checked against web.dev in late 2026; we will update the tool if Google changes them.
Real-user data vs lab tests
Search Console and the top of PageSpeed Insights show field data from real Chrome users over 28 days. That is what Google uses. The lab score below it is a single simulated test, useful for diagnosing problems but not what counts for search. Lab tests cannot measure INP at all; they show Total Blocking Time instead. If your site has little traffic, there may be no field data, and the lab results are the best guide you have.
How much does it matter?
Core Web Vitals are one of many signals Google uses, and relevant, helpful content matters more. But a slow, jumpy page loses visitors whatever its ranking, especially on mobile. Improving them is usually worth it for conversion alone.
For causes beyond these three metrics, read why is my website so slow?. On WordPress, many speed problems come from neglected plugins and themes; the WordPress Maintenance Risk Checker covers that side.