WordPress document lifecycle milestones and the Core Web Vitals

Sites with under 350ms DOMComplete document lifecycle milestones have a good LCP most often: 89%, against 70% of all WordPress sites. Sites with over 1,500ms DOMComplete DOMComplete time have it least often, at 49%.

Over 1,500ms DOMComplete is the most used: 34.2% of WordPress sites. Under 350ms DOMComplete is 12.6% of WordPress sites.

Across the four LCP sub-parts in Chrome's field data, the largest gap between under 350ms DOMComplete and over 1,500ms DOMComplete sits in time to first byte (TTFB): 691 ms median for under 350ms DOMComplete against 1621 ms for over 1,500ms DOMComplete. Overall median field LCP is 1.3s for under 350ms DOMComplete (TTFB 691 ms, load delay 252 ms, load duration 151 ms, render delay 217 ms) versus 2.5s for over 1,500ms DOMComplete.

On jQuery, 35% of sites use over 1,500ms DOMComplete document lifecycle milestones, and 69% of jQuery sites have a good LCP, against 70% of all sites. On Vue, 38% of sites use over 1,500ms DOMComplete, and 68% of Vue sites have a good LCP.

FrameworkDocument lifecycle milestones on its sitesGood LCP

WordPress sites with document lifecycle milestones 63,291 sitesOver 1,500ms DOMComplete 34%700 to 1,500ms DOMComplete 32%350 to 700ms DOMComplete 22%Under 350ms DOMComplete 13%70%

Alpine 380 sitesOver 1,500ms DOMComplete 33%700 to 1,500ms DOMComplete 31%350 to 700ms DOMComplete 24%Under 350ms DOMComplete 12%80%

jQuery 60,310 sitesOver 1,500ms DOMComplete 35%700 to 1,500ms DOMComplete 32%350 to 700ms DOMComplete 21%Under 350ms DOMComplete 11%69%

Vue 4,844 sitesOver 1,500ms DOMComplete 38%700 to 1,500ms DOMComplete 32%350 to 700ms DOMComplete 20%Under 350ms DOMComplete 10%68%

React 2,233 sitesOver 1,500ms DOMComplete 47%700 to 1,500ms DOMComplete 27%350 to 700ms DOMComplete 17%61%

Over 1,500ms DOMComplete 700 to 1,500ms DOMComplete 350 to 700ms DOMComplete Under 350ms DOMComplete

Does the framework explain the document lifecycle milestones difference?

On jQuery, 87% of sites with under 350ms DOMComplete document lifecycle milestones have a good LCP, against 48% of jQuery sites with over 1,500ms DOMComplete. Within jQuery, sites with under 350ms DOMComplete have a good LCP more often. On Vue, 87% of sites with under 350ms DOMComplete document lifecycle milestones have a good LCP, against 46% of Vue sites with over 1,500ms DOMComplete. Within Vue, sites with under 350ms DOMComplete have a good LCP more often.

What DOMInteractive and DOMComplete reveal about subresource contention

DOMInteractive marks when HTML parsing finishes and deferred scripts begin executing; DOMComplete waits for all synchronous subresources. Across 7,949 sites (12.6%) reaching DOMComplete in under 350ms, 89% pass field LCP at a 1.3s median, compared with 49% (2.5s median) on the 34.2% (21,660) exceeding 1,500ms.