You saved an image from a website and nothing will open it
Right-click, Save image as, and what lands in the Downloads folder ends in .avif. Windows Photos shrugs. Photoshop CS6 has never heard of it. The print shop's upload form rejects it. The image displayed perfectly in the browser you saved it from, which makes the failure feel like a bug. It is not. AVIF is a recent format that browsers adopted years before desktop software did, so the gap you are standing in is entirely normal — and closing in your favour every year.
What AVIF is and why sites use it
AVIF wraps still images compressed with AV1, a royalty-free video codec built by the Alliance for Open Media — Google, Netflix, Mozilla, Amazon and others — specifically to avoid the patent licensing that makes HEIC awkward. As a still-image format it is currently the most efficient in wide use.
| Format | Typical size for the same photo | Year | Transparency | HDR / 10-bit |
|---|---|---|---|---|
| JPEG | 100% (the baseline) | 1992 | No | No |
| PNG | 300–900% for photos | 1996 | Yes | No |
| WebP | 65–75% | 2010 | Yes | No |
| HEIC | 50–60% | 2015 | Yes | Yes |
| AVIF | 40–55% | 2019 | Yes | Yes |
Halving image weight is worth real money to a large site, which is why AVIF spread quickly across publishers and e-commerce. The cost lands on whoever saves the file and then wants to use it somewhere else.
Where AVIF works today
- Browsers: Chrome, Edge, Firefox, Safari 16.4 and later, and mobile browsers on current iOS and Android. This is essentially solved.
- Windows 11: Photos opens AVIF once the free AV1 Video Extension from the Store is installed; without it you get an error.
- macOS 13 and later: Preview, Quick Look and Finder thumbnails work natively.
- Editors: recent Photoshop, Affinity Photo 2, GIMP 2.10+ and Krita read it. Older perpetual-licence versions do not, and never will.
- Upload forms, print services, office software, email clients: mostly not. This is where people actually hit the wall.
Convert to JPG or PNG?
The choice follows what is in the picture, not what you plan to do with it.
- Photographs, screenshots of photographs, anything without transparency: use AVIF to JPG. The file will grow — expect roughly two to two and a half times the AVIF size at high quality — because JPEG needs more bytes for the same picture. That is the price of universal compatibility.
- Logos, icons, diagrams, anything with a transparent background: use AVIF to PNG. JPEG has no alpha channel at all, so converting a transparent AVIF to JPG fills the background with solid colour, usually black or white, and there is no way to undo that afterwards.
A quick way to tell whether transparency is present: open the AVIF in a browser tab. A transparent image sits on the page background; on Chrome's dark theme it will look like it has a dark backing. If in doubt, convert to PNG — it is lossless, so you can always make a JPG from it later, while the reverse recovers nothing.
Quality: what re-encoding costs
AVIF is lossy, so converting to JPG means decoding one lossy image and re-encoding it with a different lossy codec. Generation loss is real but small when the JPEG quality is set high. The artefacts differ in character, which is worth knowing when judging the result: AVIF tends to smooth fine detail into flat patches, while JPEG produces blocking and ringing around hard edges. An AVIF that was already compressed hard will show its existing smoothing more clearly once JPEG's sharpening-free encoding is layered on top. Converting to PNG avoids the second loss entirely, at a large cost in file size.
Avoiding AVIF downloads in the first place
Many sites serve AVIF only when the browser advertises support, using the picture element or content negotiation. Two practical consequences:
- Opening the same page in a browser without AVIF support usually yields the JPEG fallback, if the site publishes one.
- Screenshotting is a legitimate fallback for reference images — it costs quality, but a screenshot is a PNG and opens anywhere.
- Check whether the site offers an explicit download button. Downloads are often served as the original JPEG while the on-page display uses AVIF.
And a reminder that applies whenever you save an image from a site: the format problem is separate from the licensing one. Being able to open a file says nothing about being allowed to republish it.