Core Web Vitals

The Core Web Vitals measure three things. LCP describes when the largest visible content has loaded - when the page feels present. INP measures how quickly the page responds to an input. CLS captures how much the content still shifts while loading - the effect where you click something and hit something else at the last moment.

That selection is deliberately experiential rather than technical. A page can look good in measurement tools and still feel bad. So the assessment counts field data from real visitors, not the lab figure on a fast connection.

The values are rarely improved by a trick. LCP almost always hangs on oversized images or resources that block rendering. INP suffers when too much JavaScript works on the main thread. CLS mostly comes from images without fixed dimensions, late-loading fonts, and inserted banners. All three are symptoms, not settings.

So the work starts with measurement on real users, not with an optimisation checklist. We look for the actual bottlenecks instead of guessing at measures - the fastest route to a better score is almost always removing something that was never needed.