LCP Test
Lab Largest Contentful Paint against the Core Web Vitals thresholds.
Runs a real Chromium page load — usually takes 5–15 seconds.
What this tool checks
Largest Contentful Paint
Lab measurement of Largest Contentful Paint against the Core Web Vitals thresholds (good ≤ 2500ms, poor > 4000ms).
Why it matters: LCP marks when the main content becomes visible. Slow LCP makes the page feel unresponsive. This is a lab measurement from a single automated load — it is not real-user (field) data and will differ from Chrome UX Report values.
If it fails: Optimise the LCP element: serve a right-sized, modern-format image, remove render-blocking resources, and use a fast server/CDN.
Source: web.dev/articles/lcp