Direct Answer
Aim for a PageSpeed Insights score of 90+ on both mobile and desktop. Anything below 50 hurts both rankings and conversion. The score is a roll-up of Core Web Vitals plus best-practice checks; the underlying metrics (LCP, FID/INP, CLS) matter more than the headline number.
Voice answer (≤30 words)
“Aim for a PageSpeed Insights score of ninety or higher on both mobile and desktop. Below fifty hurts rankings and conversion.”
Lab vs field data: lab scores are repeatable but synthetic; field data (CrUX) is what Google actually uses for ranking.
Most quick wins are image weight, render-blocking JS/CSS, and missing cache headers.
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