How we calculate the Core Web Vitals Checker
What it measures
LCP, CLS, and INP — Google's real Core Web Vitals — for the page you enter.
How it works
- 1The tool runs a real Lighthouse audit against the page, the same engine behind Google's own PageSpeed Insights.
- 2Lab data is reported (a single, controlled test run), not field data (real aggregated user visits) — the two can differ.
Real limitations
- Lab scores can differ from real-world field data reported in Google Search Console, which reflects actual visitor conditions and devices.
- A single run is a snapshot, not a trend — performance can vary by time of day, server load, or recent changes.