By 2026, AVIF decoding is supported by the browser engines behind the large majority of web traffic : Chromium (Chrome, Edge, Opera, Brave and the rest of that family) has supported it since 2020, Firefox added support not long after, and Safari caught up starting with Safari 16 in 2022, tied to macOS Ventura and iOS 16. On paper, that reads like near-universal coverage. In practice, the gap is not in current browser versions but in how long older ones stay in circulation.
Safari's AVIF support only exists from version 16 onward, and Apple does not backport it to older OS releases the way some vendors patch older browser versions in place : a device stuck on an older iOS or macOS release for hardware or organizational reasons simply never gets it. The same pattern shows up in embedded webviews (some in-app browsers on social platforms, certain corporate device fleets running locked-down images) and in tools that render pages outside a real browser context, such as social network link-preview crawlers or some email clients that rasterize HTML. None of these show up prominently in aggregate browser-share statistics, but they are exactly where an AVIF-only strategy breaks.
WebP does not have this problem to the same degree : it reached broad support, including on older Safari versions, several years before AVIF did, which is precisely why it remains the sturdier fallback rather than JPEG or PNG. AVIF still wins on compression efficiency for most photographic content at comparable visual quality, and its encoding and decoding costs, historically a valid concern, have kept improving as hardware and software decoders matured. The realistic picture for 2026 is not "AVIF has replaced WebP" but "AVIF is the better default where it is supported, with WebP absorbing the exceptions."
This is exactly the kind of decision a merchant should not have to track browser by browser. ImagePipe negotiates the format for each request based on the Accept header the browser actually sends, in order of preference AVIF, then WebP, then JPEG or PNG, so a visitor on a locked-down corporate laptop or an older iPad gets a working image without anyone having noticed which Safari version it was running, while a visitor on a current browser gets the smaller AVIF file automatically.