jargon

Frontend & browser·Performance and Core Web Vitals

you ran the audit on your laptop, got a score of 98, and shipped a page that is slow for everyone else.

Lab data

Also calledsynthetic monitoring, lighthouse run

Measurements from a controlled synthetic run: one device, one network profile, no cache, no extensions, no real users. It is reproducible and therefore good for comparing two builds and for catching regressions in CI. It is a poor description of reality, because it has no distribution — no slow devices, no third-party variance, no returning visitors.

Commonly confused with