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Convert WebP Images to AVIF

Processed entirely in your browser. Never uploaded to a server.

Drop WebP images here or click to browse

Processed entirely in your browser. Never uploaded to a server.

If you're already serving WebP, you're already thinking about file size — AVIF is usually the next step down. It's a newer, generally more efficient format with the same broad alpha-channel support, so most sites can drop it in as a further optimization on images that are already WebP.

Expect this one to take a while

The encoder is a WebAssembly build of libavif and it's about three megabytes, downloaded once on your first conversion. AVIF encoding is slow by nature — it inherits AV1's expensive search — so a large image can take a few seconds per file. All of it runs on your device; nothing is uploaded.

FAQ

Is it worth re-encoding WebP to AVIF?
Often, yes, if file size is what you're optimizing for. AVIF is generally more efficient than WebP at the same visual quality, especially on photographic content, so images already served as WebP can frequently shrink further by moving to AVIF. The gain is usually smaller than going from PNG or JPG, though — WebP already did a decent job.
Does converting lossy WebP to AVIF lose more quality?
Yes, in principle — you're decoding an already-lossy image and running it through a second lossy encode, so a second round of compression artifacts is layered onto the first. In practice, at normal quality settings the effect is usually not visible, but it's not literally free the way a lossless conversion would be.
What happens to transparency?
Nothing bad — both WebP and AVIF support a full alpha channel, and this conversion preserves it. Transparent and partially transparent pixels in the source WebP come through to the AVIF unchanged.
Why is AVIF encoding so much slower than the WebP I started with?
AVIF is built on the AV1 video codec, and the search it performs to find an efficient encoding is far more computationally expensive than WebP's. A large image can take several seconds to encode. That's the encoder doing real work, not the page hanging.

Need broader software support instead? Go back with AVIF to WebP.

Want more control over the output size or dimensions? Try Compress Image or Resize Image.

Curious what makes AVIF different from WebP? Read AVIF explained. Before you commit to it site-wide, check where AVIF is and isn't safe to use.