Real-User Field Data (CrUX)

Alongside the lab test, LoadFocus shows real-user (field) data from the Chrome UX Report (CrUX), so you see what actual visitors experience, not just a single lab run.

Field data vs lab data

Lab data comes from a controlled, single audit run in a fixed environment, which is great for reproducible debugging and catching regressions. Field data is aggregated from real Chrome users over the trailing 28 days, so it reflects the range of devices, networks, and locations your visitors actually use. Both matter, and field data is what Google uses for the Core Web Vitals assessment.

CrUX only covers sites and pages with enough Chrome traffic, as a 28-day rolling figure. To measure every visitor yourself, per page, per device and per day, add real user monitoring (RUM) to your site.

The field-data panel

The panel shows the 75th-percentile (p75) value for each metric (LCP, INP, CLS, FCP, TTFB), colored good, needs-improvement, or poor, alongside a distribution bar that breaks down the share of visits in each band. A metric is shown only when the Chrome UX Report has enough data for it, so a site with few interactions may have no INP card.

Core Web Vitals pass/fail badge

A badge next to the panel title reads Passing Core Web Vitals when LCP, INP and CLS are all in the good band, and Core Web Vitals: needs work otherwise. It uses mobile field data, or desktop data when there is no mobile data, and it is hidden when one of the three metrics has no data yet.

Weekly trend

Each metric's info sidebar shows a weekly p75 trend with good, needs-improvement, and poor bands, so you can see real-user performance moving over time and confirm whether your changes are helping.

Thresholds

Each metric is scored against Google's published good and poor boundaries. Only LCP, INP and CLS count towards the Core Web Vitals badge; FCP and TTFB are shown as supporting metrics.

Related

• Core Web Vitals metrics
• Core Web Vitals competitor comparison
• Real user monitoring (RUM)