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Can anyone make sense of these lighthouse test results? - Printable Version

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Can anyone make sense of these lighthouse test results? - jb510 - 06-06-2019 10:17 AM

I ran a test on https://google.com/ thinking it'd rank well, but WPT's Lighthouse test gave it a 56. Then I click on the 56 and I get an 88?!?

https://www.webpagetest.org/result/190605_GW_53a8a4a1338a1fe146c2adc7e976b76d/
https://www.webpagetest.org/lighthouse.php?test=190605_GW_53a8a4a1338a1fe146c2adc7e976b76d&run=3

Further confusing things, when I run Google Page Speed Insights it gives Google a 93 mobile / 99 desktop.

I suspect GPSI is simply a "different test" even though it's based on Lighthouse. I'm just trying to _understand_ how these things so I can better understand results on other sites and specifically why "clicking the 56" on WPT leads to results so wildly different.


RE: Can anyone make sense of these lighthouse test results? - aaronpeters - 06-06-2019 05:26 PM

I agree, it is a bit confusing.

The big red 56 on the WPT test results page is the "Lighthouse PWA Score", and this is *not* the same as that 88 score you need on the Lighthouse report page.
Top right of that Lighthouse report page you see a gray marked icon and "Progressive Web App"
Click that gray icon to see more info about the PWA checks. You see some green, orange and red.

So, apparently this Lighthouse audit resulted in a 56 (our of 100) score for PWA.
This is what you see on the WPT test results page.
I think there are two things that WPT can improve here:
1. on the WPT test results page, don't show the PWA score but the Performance score
2. on the Lighthouse results page, don't show that gray icon and no score for PWA, but show the calculated score (here: 56) and use color


RE: Can anyone make sense of these lighthouse test results? - jb510 - 06-07-2019 03:37 AM

AH... funny because I've long told people GPSI was misleading because they were testing best practices for PWAs, not really testing page speed for mobile web pages.

Thanks for explaining.

I do think showing the Lighthouse performance score would make more sense.

I might even be worth doing:
if there is a valid PWA score show that (some critera that is greying it out in this case), if not fallback to the Performance Score. I'd also think showing all 5 somewhere else on the first report page would be helpful... you know if there was a square centimeter of space left to squeeze more data onto that page.

Thanks again, at least I understand now.


RE: Can anyone make sense of these lighthouse test results? - aaronpeters - 06-07-2019 03:49 AM

"I'd also think showing all 5 somewhere else on the first report page would be helpful" <= agree

Anybody using Google PageSpeed Insights really should read the explainer/FAQ:
https://developers.google.com/speed/docs/insights/v5/about?hl=en-US