JPG to AVIF converter
Convert JPG files to AVIF inside this page. No upload, no limit on how many, no watermark.
- 0 uploads
- No limits
- No signup
- Works offline
JPG and AVIF, side by side
| JPEG | AVIF | |
|---|---|---|
| Released | 1992 | 2019 |
| Compression | lossy | both |
| Transparency | no | yes |
| Animation | no | yes |
| Support | everywhere, without exception | all current browsers; limited elsewhere |
What actually changes
The most aggressive size reduction available for web images — often half the bytes of the JPEG at the same perceived quality. Encoding is slow, sometimes several seconds for a large photograph, because AV1 searches a very large space of prediction modes.
JPEG is the format the web was built on, using discrete cosine transform compression tuned for photographs, released in 1992. Its real strength is that universal compatibility — every device, browser, printer and form on earth reads it. The reason you are on this page is almost certainly the other side of that coin: no transparency, visible ringing around sharp edges and text, and a compression scheme three decades behind the state of the art.
AVIF arrived in 2019 and is a still image stored as a frame of AV1 video, with 10- and 12-bit colour and HDR support. It gives you roughly half the size of JPEG at similar quality, with far better handling of gradients and flat colour. The trade-off worth knowing about before you commit: slow to encode — seconds rather than milliseconds for a large image — and thin support outside browsers.
How the conversion works here
Your file is decoded in a Web Worker inside this browser tab — by the browser's own image pipeline where it can, and by a WebAssembly build of libheif or libavif where it cannot. The decoded pixels are then re-encoded with libavif, the same encoder Squoosh uses.
All of that happens on the processor in front of you. There is no upload step, no queue and no server, which is why there is no size cap, no daily allowance and no paid tier — and why the whole thing keeps working with the network switched off.
Doing more than one thing
Most people converting a format also need it smaller or a different size. The result screen hands your converted files straight to the compressor or the resizer in one click — no second download, no re-selecting files. If you need several formats, the general converter lets you pick the output each time.
How it works
- 01Add your JPG filesDrop them on the page, click to browse, paste from the clipboard, or drop a whole folder.
- 02Conversion runs on your deviceEach file is decoded and re-encoded as AVIF by a WebAssembly codec in a background thread. Nothing is uploaded.
- 03Adjust if you need toMove the quality slider — 90 is visually indistinguishable from the source for most photographs.
- 04DownloadSave one file, or take the whole batch as a zip built on your device.