The State of Web Vitals

Shopify iframe loading attributes and the Core Web Vitals

Default eager iframes (99.0%) versus loading="lazy" iframes (3.8%): how third-party embed scheduling affects Largest Contentful Paint across the 6,485 sites that use iframes.

Field data PhoneDesktopAll Scope All sites October 2026 edition · Desktop field outcomes · Shopify sites only
Shopify Scoped to 8,248 sites out of 203,892 analyzed (cms) Compare with all sites →
LCP Loading INP Interaction

99.0% of Shopify sites use default eager iframe loading, and 96% of those sites have a good LCP, against 97% of all Shopify sites.

The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field data · 6,485 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: 96%, against 97% of all Shopify sites.

SitesGood, needs improvement, poor LCPMedian
All Shopify sites3,81897%1.3s
Default eager iframe (no loading="lazy") 99.0%3,12396%1.3s
Lazy-loaded iframe (loading="lazy") 3.8%8795%1.2s
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field data · 6,485 sites with iframe loadingBy Arjen Karel · corewebvitals.io/state-of-cwv
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Iframe loading usage

Default eager is the most used: 99.0% of Shopify sites.

Sites using each option (sites can use more than one) 6,485 sites
Default eager iframe (no loading="lazy") 99.0%
Default eager iframe (no loading="lazy") 99.0% Lazy-loaded iframe (loading="lazy") 3.8%
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field data · 6,485 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
Shopify sites with iframe loading 2,602303 ms643 ms312 ms643 mslab 636 ms1.3s
Lazy-loaded iframe (loading="lazy") 65271 ms551 ms156 ms269 ms551 mslab 584 ms1.2s
Default eager iframe (no loading="lazy") 2,586303 ms646 ms313 ms646 mslab 637 ms1.3s
TTFB Resource load delay Resource load time Element render delay
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field data · 6,485 sites with iframe loadingBy Arjen Karel · corewebvitals.io/state-of-cwv
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Iframe loading per framework

jQuery sets the iframe loading to default eager on 99% of its sites, and 95% of jQuery sites have a good LCP, against 97% of all sites.

FrameworkIframe loading on its sitesGood LCP
Shopify sites with iframe loading 6,485 sitesDefault eager iframe (no loading="lazy") 99%97%
Vue 753 sitesDefault eager iframe (no loading="lazy") 99%97%
jQuery 2,638 sitesDefault eager iframe (no loading="lazy") 99%95%
Default eager iframe (no loading="lazy") Lazy-loaded iframe (loading="lazy")
The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field data · 6,485 sites with iframe loadingBy Arjen Karel · corewebvitals.io/state-of-cwv
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Iframe loading or the framework

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, 99.0% include default eager iframes (96% good LCP, 1.3s median LCP) - often lightweight analytics or payment sandboxes - while 3.8% use loading="lazy" (95% good LCP, 1.2s median LCP), predominantly on article pages embedding heavy video players or maps.

The State of Web Vitals · October 2026 · Shopify: 8,246 crawled sites · 3,818 with desktop field data · 6,485 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, 99.0% ship default eager iframes (96% good LCP) and 3.8% ship loading="lazy" iframes (95% 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 · Shopify: 8,246 crawled sites · 3,818 with desktop field data · 6,485 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 · 8,246 crawled Shopify sites (3,818 with desktop Chrome field data, 6,485 sites with iframe loading, October 2026) · How we measured