The State of Web Vitals

Responsive LCP image markup on Wix sites

srcset, <picture>, or a single fixed image URL: how many sites ship responsive hero candidates and how responsive markup changes Largest Contentful Paint (90% with <picture> and 96% with srcset vs 94% without).

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

Three in five Wix sites, 60.7%, have no responsive LCP image markup. Of the 39.3% that do, 75% use srcset, and 96% of those sites have a good LCP, against 94% of all Wix sites.

The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field data · 5,589 sites with responsive LCP image markupBy Arjen Karel · corewebvitals.io/state-of-cwv
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LCP pass rate

Sites with srcset responsive LCP image markup have a good LCP most often: 96%, against 94% of all Wix sites. Sites with <picture> responsive markup have it least often, at 90%.

SitesGood, needs improvement, poor LCPMedian
All Wix sites5,33394%1.2s
srcset attribute 29.5%1,57396%1.2s
No responsive markup 60.7%3,21994%1.2s
<picture> element 9.8%51190%1.3s
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field data · 5,589 sites with responsive LCP image markupBy Arjen Karel · corewebvitals.io/state-of-cwv
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Responsive LCP image markup usage

Two in five Wix sites uses responsive LCP image markup, and three in four of those use srcset.

Wix sites with responsive LCP image markup 5,589 sites
No responsive markup 60.7% Responsive LCP image markup 39.3%
Sites with responsive LCP image markup 2,197 sites
srcset attribute 75.1% <picture> element 24.9%
srcset attribute 75.1% <picture> element 24.9%
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field data · 5,589 sites with responsive LCP image markupBy Arjen Karel · corewebvitals.io/state-of-cwv
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How srcset and <picture> affect the four LCP phases

Across the four LCP sub-parts in Chrome's field data, the largest gap between srcset and no sits in resource load delay: 396 ms median for srcset against 473 ms for no. Overall median field LCP is 1.2s for srcset (TTFB 414 ms, load delay 396 ms, load duration 118 ms, render delay 167 ms) versus 1.2s for no.

Median LCP phase breakdown (Chrome field p75) Load delay Median LCP
Wix sites with responsive LCP image markup 3,917419 ms456 ms151 ms456 mslab 456 ms1.2s
srcset attribute 1,158414 ms396 ms167 ms396 mslab 396 ms1.2s
No responsive markup 2,367423 ms473 ms141 ms145 ms473 mslab 473 ms1.2s
<picture> element 392409 ms516 ms190 ms158 ms516 mslab 516 ms1.3s
TTFB Resource load delay Resource load time Element render delay
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field data · 5,589 sites with responsive LCP image markupBy Arjen Karel · corewebvitals.io/state-of-cwv
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Responsive LCP image markup per framework

On React, 61% of sites use no responsive LCP image markup, and 94% of React sites have a good LCP, against 94% of all sites.

FrameworkResponsive LCP image markup on its sitesGood LCP
Wix sites with responsive LCP image markup 5,589 sitesNo responsive markup 61%srcset attribute 30%94%
React 5,588 sitesNo responsive markup 61%srcset attribute 30%94%
No responsive markup srcset attribute <picture> element
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field data · 5,589 sites with responsive LCP image markupBy Arjen Karel · corewebvitals.io/state-of-cwv
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Responsive LCP markup or the framework

Does the framework explain the responsive LCP image markup difference?

On React, 96% of sites with srcset responsive LCP image markup have a good LCP, against 94% of React sites with no. Within React, sites with srcset and no have a good LCP about equally often.

Why srcset and <picture> matter most on mobile viewports

Without srcset or <picture>, a mobile phone on a cellular connection downloads the same 1600px or 2000px hero banner prepared for a desktop monitor. Providing width descriptors in srcset with a matching sizes attribute lets Chrome's preload scanner pick the candidate that fits the device's screen width and pixel ratio before layout runs.

The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field data · 5,589 sites with responsive LCP image markupBy Arjen Karel · corewebvitals.io/state-of-cwv
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Understanding responsive LCP image markup

Provide responsive width candidates on your LCP <img> with srcset and a matching sizes attribute, or wrap it in <picture> when art direction crops differ between mobile and desktop. Across all audited sites, 60.7% of LCP elements ship without responsive markup (94% good LCP, 1.2s median LCP), while sites using srcset reach 96% good LCP (1.2s median) and sites using <picture> reach 90% good LCP (1.3s median). Always pair srcset with an explicit sizes attribute (for example sizes="100vw" on a full-bleed hero) so Chrome does not default to assuming 100vw when the image is narrower.

Go fix it Optimize images for Core Web Vitals → Optimize the LCP image → Fix slow hero images →
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field data · 5,589 sites with responsive LCP image markupBy Arjen Karel · corewebvitals.io/state-of-cwv
Related signals LCP priority hint → LCP discovery → LCP image size → LCP origin → By Arjen Karel · 5,621 crawled Wix sites (5,333 with all devices Chrome field data, 5,589 sites with responsive LCP image markup, October 2026) · How we measured