Lab data: how PageReflect measures

Lab data is collected in a controlled environment: a Lighthouse pass run by Google's PageSpeed Insights API, once with the mobile profile and once with the desktop profile, for each page in the audit. It is repeatable, which makes it useful for comparing runs and prioritizing fixes.

If Lighthouse times out or is blocked, the pipeline continues and your report notes that lab data was partial or unavailable, rather than failing the whole run.

A PageReflect audit gathers several same-origin pages and runs the mobile and desktop Lighthouse passes on each one. The performance dimension aggregates those per-page results, so a slow template that appears on many pages shows up clearly. See Multi-page audits & sitewide scores.

Use lab data to compare runs of the same site over time, to catch regressions, and to triage prioritized fixes. Pair it with field data when you need to know what real users on real networks actually experience.