Shopify speculation rules posture and the Core Web Vitals

Sites with prefetch speculation rules pass all three Core Web Vitals most often: 86%, against 85% of all Shopify sites. The biggest gap is LCP, 98% against 95%.

Sites with prefetch speculation rules have a good LCP most often: 98%, against 95% of all Shopify sites.

Sites with prefetch speculation rules have a good INP most often: 91%, against 93% of all Shopify sites.

Sites with prefetch speculation rules have a good CLS most often: 96%, against 94% 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 80% of jQuery sites pass all three Core Web Vitals, against 85% of all sites. On Vue, 92% of sites use no, and 79% of Vue sites pass all three.

On jQuery, 94% of sites use no speculation rules, and 93% of jQuery sites have a good LCP, against 95% of all sites. On Vue, 92% of sites use no, and 94% of Vue sites have a good LCP.

On jQuery, 94% of sites use no speculation rules, and 92% of jQuery sites have a good INP, against 93% of all sites. On Vue, 92% of sites use no, and 91% of Vue sites have a good INP.

On jQuery, 94% of sites use no speculation rules, and 91% of jQuery sites have a good CLS, against 94% of all sites. On Vue, 92% of sites use no, and 90% of Vue sites have a good CLS.

FrameworkSpeculation rules on its sitesPass all three

All Shopify sites 8,246 sitesNo rules 94%85%

jQuery 3,153 sitesNo rules 94%80%

Vue 933 sitesNo rules 92%79%

No rules Prefetch Prerender

Does the framework explain the speculation rules difference?

On jQuery, 81% of sites with prefetch speculation rules pass all three Core Web Vitals, against 80% of jQuery sites with no. Within jQuery, sites with prefetch and no pass all three about equally often.

On jQuery, 98% of sites with prefetch speculation rules have a good LCP, against 92% of jQuery sites with no. Within jQuery, sites with prefetch have a good LCP more often. On Vue, 98% of sites with prefetch speculation rules have a good LCP, against 94% of Vue sites with no. Within Vue, sites with prefetch and no have a good LCP about equally often.

On jQuery, 90% of sites with prefetch speculation rules have a good INP, against 93% of jQuery sites with no. Within jQuery, sites with prefetch and no have a good INP about equally often.

On jQuery, 92% of sites with prefetch speculation rules have a good CLS, against 91% of jQuery sites with no. Within jQuery, sites with prefetch and no have a good CLS about equally often. On Vue, 94% of sites with prefetch speculation rules have a good CLS, against 89% of Vue sites with no. Within Vue, 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.