Core Web Vitals History & Competitor Comparison

example.com          (origin — most CrUX data)
competitor.com       (add up to 5)
device: mobile

Checking a single page's field data right now? Use the Core Web Vitals Checker. Want the numbers explained? Read the Core Web Vitals guide.

How to read the result

Each metric tile is coloured by its p75 value against the official Core Web Vitals thresholds:

• Good (green) — LCP ≤ 2.5 s, INP ≤ 200 ms, CLS ≤ 0.10.
• Needs improvement (amber) — between the two thresholds: LCP 2.5–4 s, INP 200–500 ms, CLS 0.10–0.25.
• Poor (red) — LCP > 4 s, INP > 500 ms, CLS > 0.25.

The card verdict rolls those three up:

• passes Core Web Vitals — all three core metrics (LCP, INP, CLS) are good.
• Not passing — at least one core metric is needs-improvement or poor.
• incomplete data / no CrUX data — CrUX has no stable sample for one or more core metrics on this target and device, so no pass verdict is asserted.

FCP and TTFB show below the core three as supporting diagnostics (they are not part of the Core Web Vitals pass). Each core tile also carries a 40-week delta so you can see direction, and the trend charts shade the good, needs-improvement, and poor bands behind every line.

Data sources & freshness

The tool calls the Google Chrome UX Report History API through a cached edge proxy. That API returns up to 40 weekly data points per metric, each the p75 across a 28-day rolling collection window, refreshed every Monday. All the charting, bucketing, and pass verdict math runs client-side in your browser from that raw response; results are cached at the edge until the next weekly refresh, so re-running a popular comparison is instant and spends no API quota.

The number for each metric is the p75 — the value 75% of real Chrome visits were at or below — which is the exact figure Google evaluates. A site only appears when it has enough Chrome traffic to form a stable sample; targets below that bar are reported as no CrUX data rather than guessed.

Features

• Up to 40 weeks of history per metric — LCP, INP, CLS, plus FCP and TTFB as diagnostics.
• Compare up to 5 origins or URLs on one chart, colour-coded per target.
• Per-site scorecard with a Core Web Vitals pass verdict and a 40-week trend delta per metric.
• Trend charts with shaded good / needs-improvement / poor bands behind every line.
• Mobile and desktop toggle — CrUX field data is kept separate per device.
• Leaderboard mode: rank a curated group or your own list of origins on any single metric or on the overall Core Web Vitals pass.
• Shareable link that restores the exact comparison, plus CSV export of every weekly value.

Limitations

This is field data, not a lab audit. It tells you what real users experienced, not which element or script caused it — for that, run a lab tool on the page. Sites without enough Chrome traffic return no data and cannot be charted, and deep URLs often have less coverage than their origin. The values reflect a trailing 28-day window and refresh weekly, so a fix you shipped this morning will not show up for days. And because CrUX is Chrome-only, traffic from other browsers is not represented.

Frequently asked questions