Google’s Chrome User Experience Report just got an experimental upgrade that changes how single-page apps are judged.
On October 13, Chrome added soft-navigation versions of all three Core Web Vitals to CrUX. Instead of only measuring the first page load, the new fields track in-app page changes where JavaScript updates the content and URL without a full reload.
What’s actually new
CrUX now exposes three experimental fields: one for Largest Contentful Paint, one for Interaction to Next Paint and one for Cumulative Layout Shift. They use the same thresholds as the stable metrics, but they count both hard loads and detected soft navigation events.
Previously, an SPA’s landing URL was charged with every interaction and layout shift that happened later in a session. The new model logs each soft navigation against its destination URL when normal eligibility rules are met.
If your site reloads on every click, Chrome’s Annie Sullivan, writing in Google’s post, is blunt about the impact. “You shouldn’t expect to see any changes in your metrics,” she writes.
The numbers that matter
Most origins won’t feel this. According to Google’s own distribution:
- Between 66% and 75% of CrUX origins get less than 5% of page views from soft navigations.
- Only 7.0% on Android and 10.6% on desktop have more than half.
- Among the top 1,000 sites, 35% on Android and 42% on desktop rely on soft navigations for most page views.
For SPA-heavy sites, the experimental scores tend to improve. Among Android origins with 75% to 100% soft navigations, the share with good LCP climbs from 26% on the stable metric to 87% when soft navigations are counted.
That doesn’t mean SPAs beat multi-page sites overall. The gain comes from measuring follow-up clicks more fairly: the second and third navigation in any site is normally faster than a cold landing page load. INP also roughly doubles its Android pass rate for SPA-heavy origins because responsiveness is now calculated per page view, not from the slowest interaction in a session.
How to read your own report
Open CrUX Vis and switch on the new ‘Include soft navigations’ toggle. You can then compare the stable and experimental versions of LCP, INP and CLS side by side for the same origin.
Pay attention to where a metric crosses a threshold. If experimental INP is still poor while LCP improves, heavy JavaScript during page transitions is probably the bottleneck. If a URL’s layout shift looks fine on first load but worsens with soft navigations, the issue may be in post-click rendering rather than initial HTML.
Keep the change in context. The September CrUX release showed 55.9% of origins passed Core Web Vitals without soft navigations, and 59.5% passed when they were counted. That’s a real but modest lift at the aggregate level.
Don’t rebuild your roadmap yet
All three metrics remain experimental. Chrome is targeting May 2027 to conclude that status, subject to feedback, and advises expecting month-to-month shifts as measurement improves. Search Console will adopt the new data only after the metrics leave the experimental stage.
The next checkpoint is November, when soft-navigation versions of First Contentful Paint and navigation types are expected. Until then, treat the new numbers as a diagnostic lens, not a ranking promise.
Source: Search Engine Journal
