WebP to AVIF Converter
Image Converter: JPG, PNG, WebP, AVIF, GIF, BMP, SVG, HEIC to AVIF
Convert still images to AVIF in your browser. Files are not uploaded. Max 100 images at a time.
Drag and drop images here, or click to select
JPG, PNG, WebP, AVIF, GIF, BMP, SVG, HEIC supported. Animated GIF, WebP and APNG stay animated when you convert to GIF.
HEIC decoding uses libheif (LGPL-3.0) through heic-to. AVIF encoding uses libavif through jSquash (Apache-2.0).
WebP to AVIF: real file size changes
| Files | WebP | AVIF | Change |
|---|---|---|---|
| 5 photos, 2400 x 1254 | 74 KB | 87 KB | +12% |
| 5 screenshots, 512 to 1440 px | 89 KB | 95 KB | -2% |
Median sizes at AVIF quality 80. The WebP files were already saved at quality 80, so a second lossy pass at the same setting did not shrink them: photos grew 10% to 16%, and screenshots ranged from 8% smaller to 7% larger.
Should you convert WebP to AVIF at all?
Updated
A WebP to AVIF converter decodes the WebP and re-encodes it with AV1 compression. That is a second lossy pass, and at the same quality setting it usually does not pay: in our sample the AVIF photos were a median of 12% larger than the WebP files they came from.
Lowering the quality slider shrinks the file, but it adds loss on top of the loss already in the WebP. If you still have the PNG or JPG original, convert that instead: PNG to AVIF saved 70% to 85% and JPG to AVIF saved 62% on photos. Use WebP to AVIF when you only have the WebP and a platform asks for AVIF.
Related guides: image converter for every format, PNG to AVIF converter, JPG to AVIF converter.
Common Questions
Why is my AVIF bigger than the WebP it came from?
A lossy WebP has already had the easy detail removed, and AVIF has to encode the WebP's compression artefacts as picture content. At the same quality number the two formats land close together, and in our sample photos grew by a median of 12%.
Which quality should I use for WebP to AVIF?
Lower it in steps of 10 from 80 and compare size and detail at 100% after each step. Every step adds another lossy pass on a file that is already lossy, so stop as soon as banding or soft text appears and keep the WebP if you never get a clear saving.
Does WebP to AVIF keep transparency?
Yes. The converter draws the WebP on a transparent canvas and AVIF stores an alpha channel, so transparent areas stay transparent. An animated WebP is the exception: it becomes a still AVIF of its first frame, because the converter does not write animated AVIF.
When is WebP to AVIF worth doing?
When the WebP is the only copy you have and a platform, CDN rule or performance budget calls for AVIF. If you can reach the PNG or JPG original, convert that instead, because the savings are much larger and you avoid a double lossy pass.
Do all browsers show AVIF as well as WebP?
MDN lists AVIF in Chrome, Edge, Firefox, Opera and Safari, and recommends fallbacks to older formats with a picture element. Many tools outside the browser read WebP but not AVIF, so keep the WebP or a JPG next to the AVIF.
Why does the first conversion take longer?
AVIF encoding runs in WebAssembly in your browser, and the page downloads an encoder of about 3.5 MB the first time you convert to AVIF. A status line shows while it loads. After that the encoder stays loaded and nothing is uploaded.