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GoogleChrome / lighthouse

Automated auditing, performance metrics, and best practices for the web.
https://developer.chrome.com/docs/lighthouse/overview/
Apache License 2.0
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pagespeed.web.dev lighthouse scores are off because CPU/Memory Power levels are not correct #16201

Open JoelLisenby opened 4 days ago

JoelLisenby commented 4 days ago

I wanted to confirm that this does appear to be the case, see evidence below:

Pagespeed insights CPU/Memory Power = 274 Lighthouse (Linux CLI) CPU/Memory Power = 3670 Lighthouse (Google Chrome Dev Tools) CPU/Memory Power = 3509

Pagespeed Insights at https://pagespeed.web.dev/: image

Lighthouse scores in headless lighthouse on ubuntu server (cli, WSL2 in Windows 11): image

Lighthouse scores in Google Chrome dev tools: image

Originally posted by @JoelLisenby in https://github.com/GoogleChrome/lighthouse/issues/12083#issuecomment-2375452955

JoelLisenby commented 4 days ago

Just to add to this, we ran a test today and are seeing Mobile scores of 93 on lighthouse locally and 53 on pagespeed.web.dev. 40 points difference, yikes! Makes sense though when the CPU / Memory throttle is simulating a device over 13X slower on pagespeed.web.dev.