Two in five Wix sites, 42.4%, have no iframe count per page. Of the 57.6% that do, 54% use 1 iframe, and 96% of those sites have a good CLS, against 96% of all Wix sites.
Two in five Wix sites, 42.4%, have no iframe count per page. Of the 57.6% that do, 36% use 2 to 3 iframes, and 100% of those sites have a good INP, against 100% of all Wix sites.
Two in five Wix sites, 42.4%, have no iframe count per page. Of the 57.6% that do, 54% use 1 iframe, and 92% of those sites have a good LCP, against 92% of all Wix sites.
Core Web Vitals pass rate
Sites with 1 iframe iframe count per page have a good CLS most often: 96%, against 96% of all Wix sites. Sites with 2 to 3 iframes iframe count have it least often, at 93%.
Sites with 2 to 3 iframes iframe count per page have a good INP most often: 100%, against 100% of all Wix sites. Sites with 1 iframe iframe count have it least often, at 99%.
Sites with 1 iframe iframe count per page have a good LCP most often: 92%, against 92% of all Wix sites. Sites with 2 to 3 iframes iframe count have it least often, at 86%.
Iframe count per page usage
Three in five Wix sites uses iframe count per page, and 54% of those use 1 iframe.
Iframe count per page per framework
On React, 42% of sites use 0 iframes iframe count per page, and 96% of React sites have a good CLS, against 96% of all sites.
On React, 42% of sites use 0 iframes iframe count per page, and 100% of React sites have a good INP, against 100% of all sites.
On React, 42% of sites use 0 iframes iframe count per page, and 92% of React sites have a good LCP, against 92% of all sites.
React 5,620 sites0 iframes 42%1 iframe 31%2 to 3 iframes 21%96%100%92%Iframe count or the framework
Does the framework explain the iframe count per page difference?
On React, 96% of sites with 1 iframe iframe count per page have a good CLS, against 97% of React sites with 0 iframes. Within React, sites with 1 iframe and 0 iframes have a good CLS about equally often.
On React, 100% of sites with 2 to 3 iframes iframe count per page have a good INP, against 100% of React sites with 0 iframes. Within React, sites with 2 to 3 iframes and 0 iframes have a good INP about equally often.
On React, 92% of sites with 1 iframe iframe count per page have a good LCP, against 95% of React sites with 0 iframes. Within React, sites with 1 iframe and 0 iframes have a good LCP about equally often.
How embedded iframes destabilize layout and multiply main-thread contexts
Every <iframe> creates an independent browsing context with its own document, styles, and scripts, and frequently resizes asynchronously after load. Across 2,381 sites (42.4%) with 0 iframes, 97% pass field CLS. Adding 1 iframe (31.2%) lowers good CLS to 96%, 2 to 3 iframes (20.7%) drops good CLS to 93%, and 4 or more iframes (5.7%, 323 sites) pulls good CLS down to 97%.
Understanding iframe count
Give every iframe container a fixed CSS aspect-ratio or min-height so async frame initialization cannot shift surrounding content, add loading="lazy" to below-the-fold embeds, and replace heavy video players with static preview facades. Across all audited sites, 42.4% use 0 iframes (97% good CLS) versus 5.7% with 4+ iframes (97% good CLS).
By Arjen Karel · 5,621 crawled Wix sites (728 with desktop Chrome field data, October 2026). How we measured.