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 88% of those sites pass all three Core Web Vitals, against 74% 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 93% of those sites have a good LCP, against 84% 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 92% 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 97% 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: 88%, against 74% of all React sites. The biggest gap is LCP, 93% against 84%.
Sites with prerender-until-script speculation rules have a good LCP most often: 93%, against 84% 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 92% of all React sites. Sites with prefetch speculation rules have it least often, at 96%.
Sites with prerender-until-script speculation rules have a good CLS most often: 97%, against 92% of all React sites. Sites with prefetch speculation rules have it least often, at 95%.
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 89% of Wix sites pass all three Core Web Vitals, against 74% of all sites. On WordPress, 89% of sites use prefetch, and 55% 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 84% of all sites. On WordPress, 89% of sites use prefetch, and 63% of WordPress sites have a good LCP.
On Wix, 90% of sites use prefetch speculation rules, and 96% of Wix sites have a good INP, against 92% of all sites. On WordPress, 89% of sites use prefetch, and 96% of WordPress sites have a good INP.
On Wix, 90% of sites use prefetch speculation rules, and 97% of Wix sites have a good CLS, against 92% of all sites. On WordPress, 89% of sites use prefetch, and 88% of WordPress sites have a good CLS.
Wix 5,824 sitesPrefetch 90%89%94%96%97%
WordPress 2,342 sitesPrefetch 89%55%63%96%88%Speculation posture or the platform
Does the platform explain the speculation rules difference?
On Wix, 88% of sites with prerender-until-script speculation rules pass all three Core Web Vitals, against 89% of Wix sites with prefetch. Within Wix, sites with prerender-until-script and prefetch pass all three about equally often. On WordPress, 56% of sites with prefetch speculation rules pass all three Core Web Vitals, against 51% of WordPress sites with no. Within WordPress, sites with prefetch and no pass all three about equally often.
On Wix, 93% of sites with prerender-until-script speculation rules have a good LCP, against 95% of Wix sites with prefetch. Within Wix, sites with prerender-until-script and prefetch have a good LCP about equally often. On WordPress, 63% of sites with prefetch speculation rules have a good LCP, against 63% 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 96% of Wix sites with prefetch. Within Wix, sites with prerender-until-script and prefetch have a good INP about equally often. On WordPress, 96% of sites with prefetch speculation rules have a good INP, against 97% of WordPress sites with no. Within WordPress, sites with prefetch and no have a good INP about equally often.
On Wix, 97% 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, 88% of sites with prefetch speculation rules have a good CLS, against 88% 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 (78% passing all three Core Web Vitals, largely WordPress 6.8 sites on conservative eagerness), 5.5% use prerender-until-script (88% passing all three, driven by Wix), and 0.3% use full prerender (56% 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 (5,488 with phone Chrome field data, October 2026). How we measured.