Hi everyone! I’m currently developing a website and decided to test its loading speed. On the PageSpeed Insights page I see different data than I see in Lighthouse in my browser. Perhaps someone can tell me what is the reason?
Also I will be glad to take advice from someone on page optimization
Here is my site Read-Only: Webflow - Hangar49 New
in general you should expect to get different results every time you run one of these tests, so don’t be surprised when they numbers change by a bit.
As for why you’d see big differences:
The result from PageSpeed Insights is showing the “Mobile” results. When you ran the Lighthouse test locally, did you run the mobile or Desktop version? It looks like Desktop from the screenshot. When it does a mobile version of the test it simulates a lower powered device, e.g.:
If they’re both running on mobile then you could check that you have the same device settings across both tests.
Another component that will introduce differences is that one is running on your local computer and the other is running somewhere in the cloud. It’s hard to know what differences that will introduce!
It only helps for a site with traffic, but a more valid way to track this is to look at the Core Web Vitals in Google Search Console or on PageSpeed Insights. That’s data from actual users visiting the website. Google doesn’t use the Performance score you see here in its ranking, but it does use the Core Web Vital scores (and bad Performance can lead to bad Core Web Vital score).
Thanks Tom for the detailed response. Yes, I checked the mobile version on both services. Unfortunately the site is still getting ready to launch and it is not possible to evaluate its Core Web Vital. But I still have a bad score in PageSpeed Insights, which I’m trying to fix (more optimized images, videos, text, scripts), but the score has only gotten worse