Speculation rules posture on React sites
Prefetch (77.5%), prerender (0.3%), prerender-until-script (5.5%), or no speculation rules (16.6%): how far ahead sites prepare the next navigation and how each posture performs on LCP, INP, and CLS.
16.6% of React sites have no speculation rules. Of the 83.4% that do, 7% use prerender-until-script, and 91% of those sites pass all three Core Web Vitals, against 76% of all React sites.
16.6% of React sites have no speculation rules. Of the 83.4% that do, 7% use prerender-until-script, and 95% of those sites have a good LCP, against 85% of all React sites.
16.6% of React sites have no speculation rules. Of the 83.4% that do, 7% use prerender-until-script, and 98% of those sites have a good INP, against 95% of all React sites.
16.6% of React sites have no speculation rules. Of the 83.4% that do, 7% use prerender-until-script, and 98% of those sites have a good CLS, against 92% of all React sites.
Core Web Vitals pass rate
Sites with prerender-until-script speculation rules pass all three Core Web Vitals most often: 91%, against 76% of all React sites. The biggest gap is LCP, 95% against 85%.
Sites with prerender-until-script speculation rules have a good LCP most often: 95%, against 85% of all React sites. Sites with prefetch speculation rules have it least often, at 85%.
Sites with prerender-until-script speculation rules have a good INP most often: 98%, against 95% of all React sites. Sites with prefetch speculation rules have it least often, at 97%.
Sites with prerender-until-script speculation rules have a good CLS most often: 98%, against 92% of all React sites. Sites with prefetch speculation rules have it least often, at 94%.
Speculation rules usage
83.4% of React sites use speculation rules, and 93% of those use prefetch. Prerender-until-script is 7% of the sites with speculation rules, 5.5% of all React sites.
Speculation rules per platform
On Wix, 90% of sites use prefetch speculation rules, and 90% of Wix sites pass all three Core Web Vitals, against 76% of all sites. On WordPress, 89% of sites use prefetch, and 54% of WordPress sites pass all three.
On Wix, 90% of sites use prefetch speculation rules, and 94% of Wix sites have a good LCP, against 85% of all sites. On WordPress, 89% of sites use prefetch, and 61% of WordPress sites have a good LCP.
On Wix, 90% of sites use prefetch speculation rules, and 97% of Wix sites have a good INP, against 95% of all sites. On WordPress, 89% of sites use prefetch, and 98% of WordPress sites have a good INP.
On Wix, 90% of sites use prefetch speculation rules, and 98% of Wix sites have a good CLS, against 92% of all sites. On WordPress, 89% of sites use prefetch, and 85% of WordPress sites have a good CLS.
Wix 5,824 sitesPrefetch 90%90%94%97%98%
WordPress 2,342 sitesPrefetch 89%54%61%98%85%Speculation posture or the platform
Does the platform explain the speculation rules difference?
On Wix, 91% of sites with prerender-until-script speculation rules pass all three Core Web Vitals, against 90% of Wix sites with prefetch. Within Wix, sites with prerender-until-script and prefetch pass all three about equally often. On WordPress, 54% of sites with prefetch speculation rules pass all three Core Web Vitals, against 52% of WordPress sites with no. Within WordPress, sites with prefetch and no pass all three about equally often.
On Wix, 95% of sites with prerender-until-script speculation rules have a good LCP, against 94% of Wix sites with prefetch. Within Wix, sites with prerender-until-script and prefetch have a good LCP about equally often. On WordPress, 61% of sites with prefetch speculation rules have a good LCP, against 59% of WordPress sites with no. Within WordPress, sites with prefetch and no have a good LCP about equally often.
On Wix, 98% of sites with prerender-until-script speculation rules have a good INP, against 97% of Wix sites with prefetch. Within Wix, sites with prerender-until-script and prefetch have a good INP about equally often. On WordPress, 98% of sites with prefetch speculation rules have a good INP, against 98% of WordPress sites with no. Within WordPress, sites with prefetch and no have a good INP about equally often.
On Wix, 98% of sites with prerender-until-script speculation rules have a good CLS, against 98% of Wix sites with prefetch. Within Wix, sites with prerender-until-script and prefetch have a good CLS about equally often. On WordPress, 85% of sites with prefetch speculation rules have a good CLS, against 84% of WordPress sites with no. Within WordPress, sites with prefetch and no have a good CLS about equally often.
How prefetch, prerender-until-script, and prerender differ in Chrome
A prefetch rule only downloads the next page's HTML document ahead of the click, removing network TTFB on the subsequent navigation while leaving subresources and rendering until after the visitor navigates. A prerender-until-script rule downloads the HTML and subresources and builds the DOM and CSSOM in a hidden renderer, pausing before JavaScript executes. A full prerender rule executes scripts and paints the next page in the background so activation is near-instant.
Understanding speculation rules posture
Use prefetch with moderate eagerness as your site-wide baseline, and use prerender or prerender-until-script on high-probability next navigations where your server and third-party scripts support background rendering. Across the dataset, 77.5% of sites use prefetch (79% passing all three Core Web Vitals, largely WordPress 6.8 sites on conservative eagerness), 5.5% use prerender-until-script (91% passing all three, driven by Wix), and 0.3% use full prerender (50% passing all three). Always exclude cart, checkout, logout, and state-mutating URLs from both prefetch and prerender rules.
By Arjen Karel · 9,570 crawled React sites (9,110 with all devices Chrome field data, October 2026). How we measured.