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 (89% with <picture> and 94% with srcset vs 92% without).
Three in five Wix sites, 60.7%, have no responsive LCP image markup. Of the 39.3% that do, 75% use srcset, and 94% of those sites have a good LCP, against 92% of all Wix sites.
LCP pass rate
Sites with srcset responsive LCP image markup have a good LCP most often: 94%, against 92% of all Wix sites.
Responsive LCP image markup usage
Two in five Wix sites uses responsive LCP image markup, and three in four of those use srcset.
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: 427 ms median for srcset against 482 ms for no. Overall median field LCP is 1.1s for srcset (TTFB 319 ms, load delay 427 ms, load duration 247 ms, render delay 148 ms) versus 1.2s for no.
Responsive LCP image markup per framework
On React, 61% of sites use no responsive LCP image markup, and 92% of React sites have a good LCP, against 92% of all sites.
React 5,588 sitesNo responsive markup 61%srcset attribute 30%92%Responsive LCP markup or the framework
Does the framework explain the responsive LCP image markup difference?
On React, 94% of sites with srcset responsive LCP image markup have a good LCP, against 92% 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.
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 (92% good LCP, 1.2s median LCP), while sites using srcset reach 94% good LCP (1.1s median) and sites using <picture> reach 89% good LCP (1.2s 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.
By Arjen Karel · 5,621 crawled Wix sites (728 with desktop Chrome field data, 5,589 sites with responsive LCP image markup, October 2026). How we measured.