Image formats on Wix sites

Sites with GIF images page image format mix have a good LCP most often: 92%, against 92% of all Wix sites. Sites with JPEG images image formats have it least often, at 87%.

AVIF images is the most used: 99.7% of Wix sites. GIF images is 98.0% of Wix sites.

Across the four LCP sub-parts in Chrome's field data, the largest gap between GIF images and JPEG images sits in time to first byte (TTFB): 343 ms median for GIF images against 447 ms for JPEG images. Overall median field LCP is 1.2s for GIF images (TTFB 343 ms, load delay 478 ms, load duration 259 ms, render delay 138 ms) versus 1.3s for JPEG images.

React sets the page image format mix to GIF images on 98% of its sites, and 92% of React sites have a good LCP, against 92% of all sites.

FrameworkPage image format mix on its sitesGood LCP

Wix sites with page image format mix 5,619 sitesAVIF images 100%GIF images / beacons 98%SVG vector graphics 69%PNG images 37%JPEG images 24%Other image formats 16%92%

React 5,618 sitesAVIF images 100%GIF images / beacons 98%SVG vector graphics 69%PNG images 37%JPEG images 24%Other image formats 16%92%

AVIF images GIF images / beacons SVG vector graphics PNG images JPEG images Other image formats WebP images

Does the framework explain the page image format mix difference?

Almost every site with GIF images page image format mix is a React site, and almost every React site has GIF images page image format mix, so the data can't tell GIF images page image format mix and React apart.

How AVIF and WebP across the page cut transfer weight and free bandwidth for LCP

Even when the LCP element itself is optimized, legacy PNG and JPEG assets elsewhere in the viewport compete for bandwidth on the same connection. Across 5,603 sites (99.7%) serving AVIF images, 92% pass field LCP (1.2s median). WebP is present on 9.3% of sites (84% good LCP), whereas legacy PNG (36.7%, 90% good LCP) and JPEG (23.8%, 87% good LCP) remain on four out of five pages.