Image loading strategies on Wix sites

Sites with lazy above-the-fold image loading strategies have a good LCP most often: 94%, against 92% of all Wix sites. Sites with lazy below-the-fold image loading have it least often, at 91%.

Eager above-the-fold is the most used: 99.2% of Wix sites. Lazy above-the-fold is 42.1% of Wix sites.

Across the four LCP sub-parts in Chrome's field data, the largest gap between lazy above-the-fold and lazy below-the-fold sits in resource load delay: 467 ms median for lazy above-the-fold against 501 ms for lazy below-the-fold. Overall median field LCP is 1.2s for lazy above-the-fold (TTFB 327 ms, load delay 467 ms, load duration 254 ms, render delay 140 ms) versus 1.3s for lazy below-the-fold.

On React, 99% of sites use eager above-the-fold image loading strategies, and 92% of React sites have a good LCP, against 92% of all sites.

FrameworkImage loading strategies on its sitesGood LCP

Wix sites with image loading strategies 5,619 sitesEager above-the-fold <img> 99%CSS background images 91%Eager below-the-fold <img> 74%Lazy below-the-fold (loading="lazy") 62%Lazy above-the-fold (loading="lazy") 42%92%

React 5,618 sitesEager above-the-fold <img> 99%CSS background images 91%Eager below-the-fold <img> 74%Lazy below-the-fold (loading="lazy") 62%Lazy above-the-fold (loading="lazy") 42%92%

Eager above-the-fold <img> CSS background images Eager below-the-fold <img> Lazy below-the-fold (loading="lazy") Lazy above-the-fold (loading="lazy")

Does the framework explain the image loading strategies difference?

On React, 94% of sites with lazy above-the-fold image loading strategies have a good LCP, against 92% of React sites with eager above-the-fold. Within React, sites with lazy above-the-fold and eager above-the-fold have a good LCP about equally often.

How browser viewport intersection gates lazy image fetches

Standard <img> elements without loading="lazy" are queued by the HTML preload scanner before layout runs (478 ms median LCP load delay on sites with eager above-the-fold images). When loading="lazy" is present on an image inside the initial viewport (42.1% of sites), Chromium withholds the network request until style and layout confirm viewport intersection, pushing median LCP resource load delay to 467 ms.