Recommendation plus a tip. PageSpeed Insights is free and the best quick CWV check, but people obsess over the 0-100 score, which is lab data.
The part that matters is the top section: “Discover what your real users are experiencing”. That’s CrUX field data, and it’s what Google actually uses.
If field data says LCP is fine, don’t waste a week chasing a lab score of 100.
This. Also if the site doesn’t have enough traffic for field data at URL level, check the origin level. And if there’s no field data at all, then the lab score is all you’ve got, but don’t treat it as gospel.
Lab score is still useful for debugging after a change though. I use it as a before/after check on staging, then watch field data over the next 28 days.
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