NO_LCP in PageSpeed Insights with Lighthouse 13.4.1 despite fully rendered page
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?
Related to #16934 – the issue is still reproducible in Lighthouse 13.4.1.
Still reproducible today with PSI using Lighthouse 13.4.1 / HeadlessChromium 151.0.7922.71:
URL tested: https://www.lewisie-zp.cz/
Fresh PSI report (18 Aug 2026, 19:51 CEST): https://pagespeed.web.dev/analysis/https-www-lewisie-zp-cz/8ra3z6al45?form_factor=desktop
Both mobile and desktop finish with NO_LCP, while the filmstrip and final screenshot show the complete WooCommerce homepage rendered correctly. The same page reports normally when Lighthouse/Performance tools are run locally in Chrome DevTools.
Evidence from the Lighthouse report:
The main document returned HTTP 200 and the final URL remained unchanged. 137 requests on mobile and 153 on desktop, with no failed or HTTP 4xx/5xx requests. is-crawlable and robots-txt both pass. No console errors or Lighthouse run warnings. Metrics contain lcpInvalidated: false, but no observed LCP entry. Stable above-the-fold candidates exist: a visible static H1 and a same-origin 800×533 image with fetchpriority="high"; neither uses opacity, transform, or an entrance animation.
Could this still be a Lighthouse 13 / PSI trace regression or infrastructure issue? Please let us know which trace artifact would be most useful if you need one.
What did you expect?
Lighthouse should detect and report the Largest Contentful Paint, calculate the Total Blocking Time, and return a valid performance score when the page is fully rendered.
What have you tried?
- Repeated the PageSpeed Insights test several times on both mobile and desktop.
- Tested the same page locally using Chrome DevTools, where the Lighthouse and Performance tools work correctly.
- Verified that the main document returns HTTP 200 and that the report contains no failed HTTP 4xx/5xx requests.
- Verified that robots.txt and crawlability checks pass.
- Checked the above-the-fold elements for opacity, transforms, and entrance animations.
- Confirmed that a static H1 and a same-origin hero image are visible LCP candidates.
How were you running Lighthouse?
PageSpeed Insights
Lighthouse Version
13.4.1
Chrome Version
No response
Node Version
No response
OS
Not applicable – PageSpeed Insights
Relevant log output
Largest Contentful Paint: Error! NO_LCP
Metrics contain:
lcpInvalidated: false
No observed Largest Contentful Paint entry was recorded.Source: GoogleChrome/lighthouse