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Some of you complain that PageSpeed Insights is a bit unrealistically show for the Lighthouse test. The PSI servers are a bit underpowered so we're changing the throttling, which should make the Performance score go up when this rolls out in the next few weeks. github.com/GoogleChrome... 🧵 1/5

You should concentrate on your field Core Web Vitals (the top part of PageSpeed Insights), and only use the lab Lighthouse Score as a very rough guide of whether Lighthouse has recommendations to improve performance or not. 100 doesn't mean perfect, it just means Lighthouse can't help anymore. 2/5

The Lighthouse Score is best for comparing two tests made on the same Lighthouse (e.g. to test and compare fixes). Performance IS—and hence LH Scores also ARE—highly variable. LH is particularly affected by where it is run from (PSI, DevTools, CI...), but also on the lots of other factors. 3/5

Lighthouse is a GREAT tool but it also can only test some things, under certain conditions. So while it's great to see people interested in improving webperf, make sure you're doing just that (improve performance) and not just improving the score. See also: en.wikipedia.org/wiki/Goodhar... 4/5

Despite all that we still feel the PSI tests are not where they should be to help give actionable insights. Therefore this change to recalibrate them will be rolling out over the current weeks. This also affects the PSI API. It will not affect other Lighthouse instances. Any questions? 5/5 🏁