WordPress layout shift causes (CLS attribution) and field CLS

Sites with web font reflow layout shift causes have a good CLS most often: 89%, against 90% of all WordPress sites. Sites with late embed growth shift causes have it least often, at 52%.

Element box growth is the most used: 78.5% of WordPress sites. Web font reflow is 24.1% of WordPress sites.

On jQuery, 79% of sites use element box growth layout shift causes, and 90% of jQuery sites have a good CLS, against 90% of all sites. On Vue, 80% of sites use element box growth, and 90% of Vue sites have a good CLS.

FrameworkLayout shift causes on its sitesGood CLS

WordPress sites with layout shift causes 44,905 sitesElement box growth (box_grow) 79%Displaced sibling element 33%Web font swap text reflow 24%90%

jQuery 43,137 sitesElement box growth (box_grow) 79%Displaced sibling element 34%Web font swap text reflow 24%90%

Vue 3,629 sitesElement box growth (box_grow) 80%Displaced sibling element 33%Web font swap text reflow 25%90%

React 1,655 sitesElement box growth (box_grow) 80%Displaced sibling element 33%Web font swap text reflow 25%88%

Element box growth (box_grow) Displaced sibling element Web font swap text reflow Unsized media expansion Late iframe / embed growth

Does the framework explain the layout shift causes difference?

On jQuery, 89% of sites with web font reflow layout shift causes have a good CLS, against 87% of jQuery sites with element box growth. Within jQuery, sites with web font reflow have a good CLS more often. On Vue, 88% of sites with web font reflow layout shift causes have a good CLS, against 87% of Vue sites with element box growth. Within Vue, sites with web font reflow and element box growth have a good CLS about equally often.

How different DOM mutations translate into field CLS failures

Not all lab layout shifts hurt real users equally. Sites whose shifts come from web font swaps (24.1%) pass field CLS 89% of the time because line-height adjustments are small. Element box growth (78.5%, 87% good CLS) and displaced siblings (33.5%, 86% good CLS) cause moderate drops, while late iframe and embed growth (0.7%) pulls field CLS down to 52% (median CLS 0.09).