Horizontal Lazy Loading demo

Horizontally scroll the grey box slowly below with the console open and caching disabled. Note when the lazy-loaded images load.

In Chrome 120-, Safari and Firefox only the first image is loaded immediately and the rest of the images should load just before being scrolled on to the screen. This is very late and often can result in a user-visible delay to the loading if the image is on screen before it's finished loading.

In Chrome 121+, the first 7 images* are loaded immediately as they are "near the viewport", and the rest are loaded as you scroll - well in advance of them being needed.

* Depending on network type. Note, DevTools network emulation does not change this.