The State of Web Vitals

Iframe loading attributes on Wix sites

Default eager iframes (99.6%) versus loading="lazy" iframes (1.0%): how third-party embed scheduling affects Largest Contentful Paint across the 3,240 sites that use iframes.

Field data PhoneDesktopAll Scope All sites October 2026 edition · Desktop field outcomes · Wix sites only
Wix Scoped to 5,623 sites out of 203,892 analyzed (cms) Compare with all sites →
LCP Loading INP Interaction

99.6% of Wix sites use default eager iframe loading, and 90% of those sites have a good LCP, against 92% of all Wix sites.

The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 728 with desktop field data · 3,240 sites with iframe loadingBy Arjen Karel · corewebvitals.io/state-of-cwv
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Core Web Vitals pass rate

Sites with default eager iframe loading have a good LCP most often: 90%, against 92% of all Wix sites.

SitesGood, needs improvement, poor LCPMedian
All Wix sites72892%1.2s
Default eager iframe (no loading="lazy") 99.6%42090%1.3s
Lazy-loaded iframe (loading="lazy") 1.0%967%1.7s
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 728 with desktop field data · 3,240 sites with iframe loadingBy Arjen Karel · corewebvitals.io/state-of-cwv
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Iframe loading usage

Default eager is the most used: 99.6% of Wix sites.

Sites using each option (sites can use more than one) 3,240 sites
Default eager iframe (no loading="lazy") 99.6%
Default eager iframe (no loading="lazy") 99.6% Lazy-loaded iframe (loading="lazy") 1.0%
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 728 with desktop field data · 3,240 sites with iframe loadingBy Arjen Karel · corewebvitals.io/state-of-cwv
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How iframe loading affects the four LCP phases

Median LCP phase breakdown (Chrome field p75) Load delay Median LCP
Wix sites with iframe loading 214372 ms510 ms263 ms510 mslab 490 ms1.3s
Default eager iframe (no loading="lazy") 213372 ms511 ms264 ms511 mslab 491 ms1.3s
TTFB Resource load delay Resource load time Element render delay
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 728 with desktop field data · 3,240 sites with iframe loadingBy Arjen Karel · corewebvitals.io/state-of-cwv
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Iframe loading per framework

React sets the iframe loading to default eager on 100% of its sites, and 92% of React sites have a good LCP, against 92% of all sites.

FrameworkIframe loading on its sitesGood LCP
Wix sites with iframe loading 3,240 sitesDefault eager iframe (no loading="lazy") 100%92%
React 3,240 sitesDefault eager iframe (no loading="lazy") 100%92%
Default eager iframe (no loading="lazy") Lazy-loaded iframe (loading="lazy")
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 728 with desktop field data · 3,240 sites with iframe loadingBy Arjen Karel · corewebvitals.io/state-of-cwv
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Iframe loading or the framework

Does the framework explain the iframe loading difference?

Almost every site with default eager iframe loading is a React site, and almost every React site has default eager iframe loading, so the data can't tell default eager iframe loading and React apart.

How embedded iframes compete for network and main-thread budget

Every eager iframe initializes a nested browsing context that fetches its own HTML, stylesheets, and scripts during page startup. Among iframe-using sites, 99.6% include default eager iframes (90% good LCP, 1.3s median LCP) - often lightweight analytics or payment sandboxes - while 1.0% use loading="lazy" (67% good LCP, 1.7s median LCP), predominantly on article pages embedding heavy video players or maps.

The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 728 with desktop field data · 3,240 sites with iframe loadingBy Arjen Karel · corewebvitals.io/state-of-cwv
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Understanding iframe loading

Add loading="lazy" to all visible below-the-fold video, map, and social iframes, or replace them with a click-to-load poster facade. Among sites with iframes, 99.6% ship default eager iframes (90% good LCP) and 1.0% ship loading="lazy" iframes (67% good LCP). Avoid putting loading="lazy" on hidden zero-pixel auth or analytics sandboxes, and never leave visible third-party media embeds eager during initial page load.

Go fix it Perfect YouTube Core Web Vitals → Google Maps with 100 percent PageSpeed → Speed up a Calendly integration →
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 728 with desktop field data · 3,240 sites with iframe loadingBy Arjen Karel · corewebvitals.io/state-of-cwv
Related signals Image format mix → Fonts per page → Font source → Script loading mix → By Arjen Karel · 5,621 crawled Wix sites (728 with desktop Chrome field data, 3,240 sites with iframe loading, October 2026) · How we measured