Choosing an image format used to mean picking between JPEG and PNG. Today the real decision is between WebP and AVIF, and the right answer depends on what you're optimizing for.
File size
AVIF typically produces smaller files than WebP at equivalent visual quality, especially on photographic content — often 20–30% smaller. WebP still wins on very small images and simple graphics, where its lighter encoding overhead pays off.
Browser support
WebP is supported everywhere that matters. AVIF support is now strong across modern Chrome, Firefox, Edge, and Safari, but older devices and some in-app browsers still don't decode it — which is why serving AVIF with a WebP fallback (and JPEG behind that) remains the safest default.
Encoding speed
AVIF encoding is noticeably slower than WebP, which matters if you're transforming images on request rather than caching aggressively. This is exactly what pixpoo's edge cache is built to absorb — the first request pays the encoding cost, every request after that is served from cache.
Our recommendation
Serve AVIF where the client supports it, WebP as the fallback, and keep a JPEG behind that for anything ancient. pixpoo's /v1/images/transform endpoint does this negotiation automatically when you pass format=auto.