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Black BoxPersonalization

Understand

Page speed test

Google PageSpeed Insights runs Lighthouse against a page on this site and, when Chrome has enough visits, adds field data from the last 28 days.

Lab data and field data

Lab data is one Lighthouse visit that Google runs when you press the button, on a controlled phone or desktop profile. The four scores and the lab metrics come from that visit.

Field data is the Chrome User Experience Report. The numbers are the 75th percentile of real Chrome visits over the last 28 days, once for this URL and once for the whole origin. A lab score can move on the next run. Field data moves when enough people have visited.

The URL Google measures is the public site plus the path you pick. This page’s own Core Web Vitals, from this browser, stay on Performance.

Categories are performance, accessibility, best practices, and SEO. A repeat of the same URL and strategy within 15 minutes reuses the saved result. The server allows a handful of new Google calls every 10 minutes. When PAGESPEED_API_KEY is set, the server sends it to Google and leaves it off this page. When it is unset, the call is keyless, and Google’s shared daily quota is often already used up.

Score history

Each new call to Google stores the four category scores for this path. The chart is the performance score. Apply drizzle/0009_pagespeed.sql on Neon before production rows are kept.

No stored run for this page yet.

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