WordPress main-thread CPU breakdown and the Core Web Vitals

Sites with 450 to 1,200ms of scripting CPU main-thread CPU breakdown have a good INP most often: 98%, against 97% of all WordPress sites. Sites with over 1,200ms of scripting CPU scripting CPU have it least often, at 95%.

Over 1,200ms of scripting CPU is the most used: 35.1% of WordPress sites. 450 to 1,200ms of scripting CPU is 29.4% of WordPress sites.

On jQuery, 36% of sites use over 1,200ms of scripting CPU main-thread CPU breakdown, and 97% of jQuery sites have a good INP, against 97% of all sites. On Vue, 41% of sites use over 1,200ms of scripting CPU, and 95% of Vue sites have a good INP.

FrameworkMain-thread CPU breakdown on its sitesGood INP

All WordPress sites 63,295 sitesOver 1,200ms scripting CPU 35%450 to 1,200ms scripting CPU 29%150 to 450ms scripting CPU 21%Under 150ms scripting CPU 14%97%

jQuery 60,314 sitesOver 1,200ms scripting CPU 36%450 to 1,200ms scripting CPU 30%150 to 450ms scripting CPU 21%Under 150ms scripting CPU 13%97%

React 2,233 sitesOver 1,200ms scripting CPU 47%450 to 1,200ms scripting CPU 28%150 to 450ms scripting CPU 17%96%

Vue 4,844 sitesOver 1,200ms scripting CPU 41%450 to 1,200ms scripting CPU 32%150 to 450ms scripting CPU 20%95%

Alpine 380 sitesOver 1,200ms scripting CPU 35%450 to 1,200ms scripting CPU 34%150 to 450ms scripting CPU 22%88%

Over 1,200ms scripting CPU 450 to 1,200ms scripting CPU 150 to 450ms scripting CPU Under 150ms scripting CPU

Does the framework explain the main-thread CPU breakdown difference?

On jQuery, 98% of sites with 450 to 1,200ms of scripting CPU main-thread CPU breakdown have a good INP, against 95% of jQuery sites with over 1,200ms of scripting CPU. Within jQuery, sites with 450 to 1,200ms of scripting CPU have a good INP more often. On Vue, 97% of sites with 450 to 1,200ms of scripting CPU main-thread CPU breakdown have a good INP, against 93% of Vue sites with over 1,200ms of scripting CPU. Within Vue, sites with 450 to 1,200ms of scripting CPU have a good INP more often.

Why scripting dominates main-thread CPU budgets

Across the web, JavaScript evaluation accounts for the largest share of total main-thread CPU time, dwarfing HTML parsing, style calculation, and painting. Across 13,281 sites (21.0%) spending 150 to 450ms in scripting CPU, 98% pass field INP (91ms median), while the 35.1% (22,247) exceeding 1,200ms drop to 95% good INP (105ms median).