Lighthouse fails to detect FCP on all sites #16642
Description
FAQ
- Yes, my issue is not about variability or throttling.
- Yes, my issue is not about a specific accessibility audit (file with axe-core instead).
- Yes, my issue is not answered by other FAQs.
URL
What happened?
I've been re-writing my personal blog and have been working on it's lighthouse score. I kept getting error NO_FCP on all sites I try it on, including the google homepage. I can see the page display quickly while lighthouse is running, but the report keeps running until the 15 second timeout.
What did you expect?
Lighthouse to detected when the page is finished rendering and give a report.
What have you tried?
- Running lighthouse in chrome
- Re-installing chrome (flatpak)
- Running lighthouse in chromium
- Running lighthouse at the command line
- Running against local preview server
- Running against my site deployed to cloudflair (https://astro-rewrite.buchanan-blog.pages.dev/)
- Running against https://google.com
How were you running Lighthouse?
Chrome DevTools
Lighthouse Version
12.6.1
Chrome Version
139.0.0.0
Node Version
22.15.0
OS
Linux Fedora 42