Field data from real visitors

Field data comes from real people on their own phones, laptops, and networks. Lab data comes from one controlled test. The two often disagree, and neither is wrong: they answer different questions.

PageReflect reports contain lab data only. We run Lighthouse through Google's PageSpeed Insights API and read the Lighthouse result. We do not pull Chrome UX Report (CrUX) data, and we do not put a tracking script on your site. A report can't tell you what your visitors actually experienced.

CrUX is Google's public dataset of Core Web Vitals, collected from Chrome users who opted in. It reports the 75th percentile over a rolling 28 days, so a fix you ship today takes weeks to show up in full.

Low-traffic sites and pages often have no CrUX data at all. That is common for small business sites, and in that case lab data is what you have to work with.

Open the Core Web Vitals report in Google Search Console if you have verified the site. It groups URLs by status and is the closest view to how Google sees your pages. PageSpeed Insights also shows CrUX numbers above its lab results when they exist for a URL.

Use PageReflect to compare runs and catch regressions right after a release, since you get a number in minutes. Use field data to check whether those changes reached real visitors.

If lab scores look good and field numbers don't, look at slower devices and mobile networks first, then at scripts that load after a visitor interacts or scrolls. A single lab run misses a lot of that. See Lab data and Core Web Vitals.