Convert WebP to AVIF
Drop a WebP file below and get a AVIF back. The conversion happens on your own machine, so nothing is uploaded and there is no size or quantity limit beyond what your browser can hold in memory.
Drop images here
Ctrl/⌘ VPaste a screenshot or copied image
Accepts WebP
Lower means a smaller file. 75 is a good default for photos.
100% in your browser Files are never uploaded.
Why convert WebP to AVIF?
For the same picture, AVIF usually lands well under the size of the WebP original. That matters when you are trimming page weight or squeezing under an upload limit.
Both formats are lossy. Every re-encode discards a little more detail, so it is worth starting from the original rather than from a copy that has already been through this a few times.
Both of these are modern web formats and WebP is already good, so the honest first question is whether this conversion is worth doing at all. AVIF is meaningfully more efficient — but you are starting from an image that has already been through a lossy encoder once, and that changes the arithmetic considerably.
Before you convert
The advertised gains assume you start from an original
The figures usually quoted for AVIF versus WebP come from encoding both from the same untouched source. Encoding AVIF from a WebP is a second lossy pass: the detail WebP discarded is already gone, and AVIF now spends bytes faithfully reproducing WebP's artefacts. Real-world savings in this direction are typically a fraction of the headline number. If the original file still exists anywhere, encode from that instead — it is not a small difference.
You are also trading away some compatibility
WebP has had universal browser support for years and its long tail of older devices has mostly aged out. AVIF arrived later, so that tail is still meaningfully longer — some in-app browsers, older phones and most email clients will not render it. For a site already serving WebP successfully, the bytes saved may not justify adding a fallback layer you did not previously need.
When it does make sense
Large photographic hero images, where AVIF's advantage is biggest and a few hundred kilobytes actually move your loading metrics. For icons, small thumbnails and flat-colour graphics, the gain is marginal and lossy AVIF can soften edges — leave those as WebP.
What carries over
- Transparency
- Pixel dimensions
- Some further size reduction
What does not
- A little detail — this is a second lossy pass
- Support on older devices and in email
- Animation, if the source had any
WebP vs AVIF at a glance
| Property | WebP | AVIF |
|---|---|---|
| Compression | Lossy | Lossy |
| Transparency | Yes | Yes |
| Typical file size | 65-75% of an equivalent JPEG | 40-55% of an equivalent JPEG |
| Compatibility | Supported by all current browsers and most apps | All current browsers; some older desktop apps lag behind |
| Usually comes from | Websites optimising page weight | Websites optimising page weight |
Frequently asked questions
Are my WebP files uploaded anywhere?
No. The decoder and encoder are WebAssembly modules that run inside this page. The network tab may show a codec downloading the first time you use a format, but no request contains your file. On supported browsers, a codec that has already been used is cached so the same conversion can work offline.
Is there a file size or quantity limit?
There is no limit imposed by us. The practical ceiling is your device’s memory, since the image has to be held uncompressed while converting. On a typical laptop, images up to around 100 megapixels convert without trouble.
Will converting to AVIF lose quality?
AVIF is a lossy format, so some data is discarded. At the default quality setting the difference is not visible at normal viewing sizes. If you need an exact copy of the pixels, choose PNG instead.
Does it work on a phone?
Yes. The same WebAssembly modules run on mobile browsers. Conversion is slower than on a desktop because phone CPUs are weaker, and very large images are more likely to hit memory limits.
Why did I end up with a WebP file?
Most websites now serve WebP because it is smaller than JPEG, so saving an image from a web page usually hands you one. Browsers support it well, desktop software noticeably less so — which is why converting it away is such a common need.
Where does AVIF actually work?
Every major browser decodes AVIF natively, so it is safe for use on the web. Desktop applications lag further behind — plenty of image viewers and editors still cannot open it. Encoding is also noticeably slower than the other formats here, so expect a large image to take a few seconds.