Page-experience measurements, reported as the lab signal they are

What the source requires

Core Web Vitals are assessed on field data — "a good threshold to measure is the 75th percentile of page loads, segmented across mobile and desktop devices". A single measurement taken by us is a lab measurement, and web.dev is direct about the limit: "While lab measurement is an essential part of delivering great experiences, it is not a substitute for field measurement."

Why this is hard to satisfy

Vendors quote a one-off lab score as though it were the metric that counts. It is not the same number, and a practice acting on it can spend money moving a figure no user experiences.

What we do about it

Measure and report the lab signal, labelled as lab, alongside field data where the practice has authorised access to it. We never present a lab figure as the assessed metric, and we never convert either into a ranking claim.

In build · phase three