Google added experimental soft navigation metrics to CrUX (Chrome User Experience Report, the public dataset Chrome uses to track real-user page performance) on October 13, according to Search Engine Journal. For owners of single-page applications, or SPAs (sites that update page content without a full browser reload), each in-app page change now gets its own Core Web Vitals measurement in the new experimental fields, rather than being absorbed into the first page load’s data. Google’s stable scores are unchanged for now.
What changed in CrUX on October 13?
Three new experimental fields are now available in BigQuery (Google’s cloud data warehouse for running large-scale queries), the CrUX API, and the History API, per Search Engine Journal. The fields are experimental_largest_contentful_paint_with_softnavs, plus equivalent fields for INP and CLS. They measure the same things as the stable versions but count both hard page loads and detected soft navigation events. CrUX Vis also added an “Include soft navigations” toggle to compare both metric versions side by side.
Before this update, CrUX only tracked an SPA’s first load. Every subsequent in-app click was grouped with that initial load, with all interactions and layout shifts attributed back to the landing URL. Now, any user action that changes both the visible content and the URL is tracked separately and measured under the destination URL. The underlying data comes from Chrome’s Soft Navigations API, which has been on by default since Chrome Version 151, released July 28, per Search Engine Journal.
Which sites will soft navigations actually affect?
Most sites probably won’t notice much of a difference. About 70% of origins in CrUX have little or no soft navigation traffic, per Search Engine Journal. Between 66% and 75% of origins, depending on platform, have fewer than 5% of page views as soft navigations. Annie Sullivan, who authored the Google post, put it plainly: “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.”
The pattern shifts at the top of the traffic scale. Among the top 1,000 sites, 35% on Android and 42% on desktop rely on soft navigations for more than half of their page views, per Search Engine Journal.
How much do soft navigations change LCP, INP, and CLS scores?
Significantly, for SPA-heavy sites. For Android origins where 75% to 100% of page views are soft navigations, the share earning a “good” LCP (Largest Contentful Paint, the time it takes for the main visible content to load) score rises from 26% on the stable metric to 87% on the experimental one, per Search Engine Journal.
Sullivan explained the reason: “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 (Interaction to Next Paint, measuring how quickly a page responds to a user’s click or tap) roughly doubles Android pass rates for sites relying mainly on soft navigations. SPA-heavy sites still lag behind multi-page sites on INP, and heavy JavaScript during page changes can affect it, per Search Engine Journal.
CLS (Cumulative Layout Shift, measuring how much page elements move unexpectedly) improvements put SPA-heavy desktop sites on par with multi-page sites. Android remains slightly behind, per Search Engine Journal.
At the aggregate level, the September CrUX dataset shows 55.9% of all origins passing Core Web Vitals without soft navigations counted, rising to 59.5% when they are included, per Search Engine Journal.
What is the timeline to stable status?
Chrome aims to conclude the experimental phase by May 2027, subject to feedback, per Search Engine Journal. In the Web Vitals lifecycle, metrics move from experimental to pending for at least six months before becoming stable. Search Console will adopt the new data once the metrics leave the experimental stage. The November CrUX release is the next checkpoint, when soft-navigation versions of FCP (First Contentful Paint, the time until any content first appears on screen) and navigation types are expected. Chrome advises treating month-to-month numbers as directional rather than final while the measurement continues to improve.
Before acting on the new numbers, check these first
- Confirm whether your site is an SPA: does page content update without a full browser reload when users click navigation links?
- Open CrUX Vis and enable the “Include soft navigations” toggle to compare stable and experimental scores for your origin side by side.
- Review your share of soft navigation page views in BigQuery or the CrUX API to understand how much the new fields apply to your traffic.
- Check experimental LCP, INP, and CLS scores against Google’s passing thresholds to see how the experimental picture differs from your current stable scores.
- Treat current numbers as directional; expect month-to-month shifts as Chrome refines the measurement before the May 2027 target.
- Watch the November CrUX release for FCP soft-navigation data and any updates to the timeline or methodology.
- Submit feedback through the web-vitals feedback group or the soft navigations spec repository on GitHub if your site shows unexpected results.
What this means for AI-search visibility
The practical takeaway for SPA-based brands: the experimental numbers may show better Core Web Vitals than the stable data does today. Google’s stable scores are unchanged for now, and Search Console will only switch once the metrics leave the experimental stage, which Chrome aims to conclude in May 2027.
The LCP data Search Engine Journal reported illustrates the scale. Android origins with mostly soft navigations go from 26% “good” on the stable metric to 87% on the experimental one. That is not a marginal rounding difference. It is a substantially different picture of the same site.
In Hingewise’s view, any link to AI-search visibility is indirect at best: the source does not connect these metrics to rankings or AI answers. What the new data does give SPA owners is a more accurate picture of real-user performance, a better basis for deciding whether performance work deserves priority.
Benchmarking the experimental scores now gives SPA owners an early view of how their numbers may look once Search Console adopts the new data, with the caveat Chrome gives: expect some shifts from month to month as the measurement improves.
Source: Search Engine Journal, October 13
Lam Nguyen · Hingewise
This article was drafted with AI assistance from the sources cited above and checked against them before publishing. The "What this means for AI-search visibility" section is Hingewise's editorial analysis, built on the frameworks and positions we use in our GEO work. How we work: Editorial policy.