Speculation rules eagerness on React sites
Conservative, moderate, eager or immediate: which speculation rules sites use, and whether those sites pass LCP, INP and CLS more often.
16.6% of React sites have no speculation rules. Of the 83.4% that do, 72% use eager, and 89% 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, 72% use eager, and 95% 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, 72% use eager, and 96% 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, 72% use eager, and 98% of those sites have a good CLS, against 92% of all React sites.
Core Web Vitals pass rate
Sites with eager speculation rules pass all three Core Web Vitals most often: 89%, against 74% of all React sites. The biggest gap is LCP, 95% against 84%.
Sites with eager speculation rules have a good LCP most often: 95%, against 84% of all React sites. Sites with conservative rules have it least often, at 64%.
Sites with eager speculation rules have a good INP most often: 96%, against 92% of all React sites. Sites with conservative rules have it least often, at 96%.
Sites with eager speculation rules have a good CLS most often: 98%, against 92% of all React sites. Sites with conservative rules have it least often, at 88%.
Speculation rules usage
83.4% of React sites use speculation rules, and 72% of those use eager.
Speculation rules per platform
Wix sets the speculation rules to eager on 99% of its sites, and 89% of Wix sites pass all three Core Web Vitals, against 74% of all sites. WordPress sets the speculation rules to conservative on 89% of its sites, and 55% of WordPress sites pass all three.
Wix sets the speculation rules to eager on 99% of its sites, and 94% of Wix sites have a good LCP, against 84% of all sites. WordPress sets the speculation rules to conservative on 89% of its sites, and 63% of WordPress sites have a good LCP.
Wix sets the speculation rules to eager on 99% of its sites, and 96% of Wix sites have a good INP, against 92% of all sites. WordPress sets the speculation rules to conservative on 89% of its sites, and 96% of WordPress sites have a good INP.
Wix sets the speculation rules to eager on 99% of its sites, and 97% of Wix sites have a good CLS, against 92% of all sites. WordPress sets the speculation rules to conservative on 89% of its sites, and 88% of WordPress sites have a good CLS.
Wix 5,824 sitesEager 99%89%94%96%97%
WordPress 2,342 sitesConservative 89%55%63%96%88%Speculation rules or the platform
Does the platform explain the speculation rules difference?
Almost every site with eager speculation rules is a Wix site, and almost every Wix site has eager speculation rules, so the data can't tell eager speculation rules and Wix apart. On WordPress, 56% of sites with conservative speculation rules pass all three Core Web Vitals, against 51% of WordPress sites with none. Within WordPress, sites with conservative and none pass all three about equally often.
Almost every site with eager speculation rules is a Wix site, and almost every Wix site has eager speculation rules, so the data can't tell eager speculation rules and Wix apart. On WordPress, 63% of sites with conservative speculation rules have a good LCP, against 63% of WordPress sites with none. Within WordPress, sites with conservative and none have a good LCP about equally often.
Almost every site with eager speculation rules is a Wix site, and almost every Wix site has eager speculation rules, so the data can't tell eager speculation rules and Wix apart. On WordPress, 96% of sites with conservative speculation rules have a good INP, against 97% of WordPress sites with none. Within WordPress, sites with conservative and none have a good INP about equally often.
Almost every site with eager speculation rules is a Wix site, and almost every Wix site has eager speculation rules, so the data can't tell eager speculation rules and Wix apart. On WordPress, 88% of sites with conservative speculation rules have a good CLS, against 88% of WordPress sites with none. Within WordPress, sites with conservative and none have a good CLS about equally often.
How much speculation rules speed up the next page
Speculation rules only speed up the page a visitor opens next, not the page they land on, and Chrome's field data counts both. A prefetch fetches the next page's HTML early, which takes time off its TTFB and its LCP. A prerender also builds the next page before the click, so it can open with an LCP close to zero and its layout shifts happen out of sight. In Shopify's test, moderate cut the median LCP of the next page by 228 ms on desktop compared with conservative, and by 24 ms on phones.
Understanding speculation rules eagerness
Use eager. Sites with eager speculation rules pass all three Core Web Vitals most often, and the theory fits: the earlier Chrome starts, the more of the next page is ready when the visitor clicks. Almost all of those sites are Wix sites, so part of that lead is the platform. The cost is pages loaded that nobody opens, so check that your server can take the extra requests. Conservative waits until the visitor presses a link. Moderate starts after a 200 ms hover on desktop, and on a phone half a second after scrolling stops near a link. Eager starts after a 10 ms hover on desktop, and on a phone once a link has been on screen for 50 ms. Immediate starts as soon as Chrome reads the rule. On WordPress, core uses conservative, which made no visible difference in this data; the wp_speculation_rules_configuration filter switches it to eager.
By Arjen Karel · 9,570 crawled React sites (5,488 with phone Chrome field data, October 2026). How we measured.