Why Google Lighthouse and PageSpeed Insights provide different results?

page speed insights is run in a datacenter somewhere and will definitely have different performance characteristics than running Lighthouse on your local machine.


Pagespeed’s test machines are more than likely slower than your local desktop, and are causing scores to be lower than if you run them on your machine.


Pagspeed didn’t use lighthouse before v5 and wasn’t actually performing analysis of your site, but more checking it against a bunch of static rules (eg: compress your scripts, use small images) and it added up to a final score. That’s why it was more consistent.


See also: Online speed benchmarking tools for websites