Chrome published experimental Core Web Vitals that count soft navigations in the Chrome User Experience Report on October 13. For SPA-heavy Android origins, the share passing the LCP threshold jumps from 26% on the stable metric to 87% on the experimental one. Chrome targets May 2027 to end the metrics' experimental status, subject to feedback.

The release adds three fields to CrUX: experimental_largest_contentful_paint_with_softnavs, plus one each for INP and CLS. They measure the same things as the stable fields. The difference: they count hard loads and detected soft navigation events together. The data is live in BigQuery, the CrUX API and the History API, and CrUX Vis now includes an "Include soft navigations" toggle for side-by-side comparison.

What changed in measurement?

Previously, CrUX measured only an SPA's first load. Every subsequent in-app change was grouped with that first load, and all interactions and layout shifts were attributed to the landing URL. Now, when a user action changes both content and URL, Chrome tracks that event individually under the destination URL, subject to normal eligibility criteria.

The data comes from the Soft Navigations API, on by default since Chrome 151 shipped July 28. Chrome defines a soft navigation as a user action that produces both a visible URL change and a visible paint. The origin trial ran in August 2025 before CrUX integration was announced.

Which sites see movement?

Most won't. About 70% of origins in CrUX have little or no soft navigation traffic. Google's post sorts origins by the share of page views that are soft navigations, and between 66% and 75% of origins sit below 5%, depending on platform. Only 7.0% on Android and 10.6% on desktop exceed half.

The top 1,000 sites skew differently: 35% on Android and 42% on desktop rely on soft navigations for more than half of page views. Annie Sullivan, who authored the post, said: "If your site doesn't use JavaScript to dynamically swap out page content and update the URL without a full browser reload, you shouldn't expect to see any changes in your metrics."

How do the scores shift?

All three metrics improve for sites where more than half of page views are soft navigations. The 26%-to-87% good-LCP gap on Android comes from a measurement correction, not an SPA speed advantage. Sullivan writes: "This isn't because SPAs are faster than multi-page websites (MPAs) overall, but because follow-up clicks are faster on any site, bringing SPAs with many follow-up visits in line with MPAs with many follow-up visits."

INP improves because responsiveness is now measured per page view rather than by the slowest interaction across a session. Google says this roughly doubles Android pass rates for sites that rely mainly on soft navigations. SPA-heavy sites still trail multi-page sites on INP, so heavy JavaScript during page changes can drag it down.

CLS also gains from grouping layout shift events by view instead of session. That puts SPA-heavy desktop sites on par with multi-page sites; Android remains slightly behind.

The September dataset release notes quantify the aggregate effect: 55.9% of all origins passed Core Web Vitals without soft navigations counted. With them counted, the figure rose to 59.5%.

Which numbers are confirmed, and which are provisional?

Google's stable scores are unchanged. That is confirmed. The experimental figures may move. Chrome advises readers to "expect some shifts from month to month as the measurement improves," so treat the new numbers cautiously until they stabilize. Search Console will adopt the new data only after the metrics leave the experimental stage.

For practical use, SPA-heavy site owners can enable the CrUX Vis toggle to compare both versions of each metric and check which ones change most against Google's thresholds. On sites that reload with every click, the toggle makes no difference.

What comes next?

The November CrUX release is the next checkpoint, with soft-navigation versions of FCP and navigation types expected. In the Web Vitals lifecycle, metrics move from experimental to pending for at least six months before becoming stable, and Google has not said which stage comes next. Chrome invites feedback through the web-vitals feedback group and the soft navigations spec repository on GitHub. Monitor the release notes for updates to the May 2027 target and for when Search Console begins the switch.