Convert WebP to AVIF — Free, Fast & Private
This is an unusual conversion, because you are not fixing a compatibility problem — WebP already works nearly everywhere. You are chasing file size. AVIF, built on the AV1 video codec, typically lands 20–30% below a WebP of comparable visual quality, and the gap widens as you push quality down.
That makes this worth doing for one situation in particular: a site already serving WebP where images remain the bulk of the page weight. Everywhere else, the honest answer is that WebP is fine and the conversion is not worth the effort.
What survives the conversion, and what does not
Transparency survives. Both formats carry a full 8-bit alpha channel, so a WebP with a soft shadow or an anti-aliased logo edge converts cleanly, with no halo and no matte colour baked in.
Animation does not. WebP supports animation, and this converter is frame-based — an animated WebP yields a single still image, not an animated AVIF. If your file is animated, this is the wrong tool. Keep it as animated WebP.
Colour depth is capped by the source. AVIF can carry 10- and 12-bit colour and HDR, which is one of its real advantages over WebP. But WebP is 8-bit only, so converting from WebP cannot invent depth that was never there. You get AVIF’s compression efficiency, not its colour range.
Generation loss is real here
Both formats are lossy. A WebP that was already compressed from a JPEG has been through two lossy encoders; converting to AVIF makes three. Each pass throws away detail the next one cannot recover, and artefacts from the earlier pass get faithfully encoded as if they were real detail.
If you still hold the original — the camera file, the PNG export, the master — encode AVIF from that instead. You will get a smaller file and a better-looking one. Convert from WebP only when the WebP is all you have.
Browser support, honestly stated
AVIF encoding happens on your device, so it depends on your browser. MiniPx probes for a working AVIF encoder and only offers the format when one is present — the option is hidden rather than silently producing something else. Chrome and Edge on desktop are reliable; some browsers advertise AVIF support and then quietly return a PNG, which MiniPx detects by checking the file’s magic bytes and rejects rather than handing you a 3 MB PNG with an .avif extension.
For display, AVIF is supported by all current major browsers, but a meaningful tail of older devices is not covered. Serve AVIF with a WebP or JPEG fallback in a <picture> element rather than replacing your WebP files outright.
If you decide AVIF is a step too far, converting AVIF back to WebP works too, and the AVIF vs WebP vs JPEG comparison covers the trade-offs in more depth.