Switching a gallery to AVIF saved 4.1 MB and 1.3s of LCP

Switching a gallery to AVIF saved 4.1 MB and 1.3s of LCP

AVIF is a newer image format that squeezes photos far smaller than JPEG with no visible quality loss. Think of it like vacuum-packing a suitcase: same clothes, half the space.

A photography gallery served 20 JPEGs averaging 280 KB each. The big lead image made LCP — Largest Contentful Paint — land at 3.4s.

What was done:

— Converted the photos to AVIF, dropping the average to 90 KB.
— Used a <picture> tag offering AVIF first, JPEG as a fallback for older browsers.
— Total page weight fell by 4.1 MB.

Result: LCP dropped to 2.1s, with no loss anyone could see.

Try this: convert one large photo to AVIF and compare sizes. If your browsers support it, the <picture> fallback keeps everyone covered. Easier than it sounds, promise.