Shopify speculation rules posture and the Core Web Vitals

Sites with prefetch speculation rules pass all three Core Web Vitals most often: 84%, against 83% of all Shopify sites. The biggest gap is INP, 100% against 99%.

Sites with prefetch speculation rules have a good LCP most often: 97%, against 97% of all Shopify sites.

Sites with prefetch speculation rules have a good INP most often: 100%, against 99% of all Shopify sites.

Sites with prefetch speculation rules have a good CLS most often: 87%, against 86% of all Shopify sites.

6.3% of Shopify sites use speculation rules, and 95% of those use prefetch.

On jQuery, 94% of sites use no speculation rules, and 76% of jQuery sites pass all three Core Web Vitals, against 83% of all sites. On Vue, 92% of sites use no, and 77% of Vue sites pass all three.

On jQuery, 94% of sites use no speculation rules, and 95% of jQuery sites have a good LCP, against 97% of all sites. On Vue, 92% of sites use no, and 97% of Vue sites have a good LCP.

On jQuery, 94% of sites use no speculation rules, and 99% of jQuery sites have a good INP, against 99% of all sites. On Vue, 92% of sites use no, and 100% of Vue sites have a good INP.

On jQuery, 94% of sites use no speculation rules, and 80% of jQuery sites have a good CLS, against 86% of all sites. On Vue, 92% of sites use no, and 80% of Vue sites have a good CLS.

FrameworkSpeculation rules on its sitesPass all three

All Shopify sites 8,246 sitesNo rules 94%83%

Vue 933 sitesNo rules 92%77%

jQuery 3,153 sitesNo rules 94%76%

No rules Prefetch Prerender

Does the framework explain the speculation rules difference?

On jQuery, 79% of sites with prefetch speculation rules pass all three Core Web Vitals, against 76% of jQuery sites with no. Within jQuery, sites with prefetch and no pass all three about equally often.

On jQuery, 97% of sites with prefetch speculation rules have a good LCP, against 95% of jQuery sites with no. Within jQuery, sites with prefetch and no have a good LCP about equally often.

On jQuery, 100% of sites with prefetch speculation rules have a good INP, against 99% of jQuery sites with no. Within jQuery, sites with prefetch and no have a good INP about equally often.

On jQuery, 82% of sites with prefetch speculation rules have a good CLS, against 80% of jQuery sites with no. Within jQuery, 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.