Why you end up with AVIF files
AVIF is an image format built on the AV1 video codec. At the same visual quality its files are much
smaller than JPG, so many websites, shops and image services now send AVIF to any browser that can show
it. You never see the difference on the page. You see it when you save the picture: the file is the one
the site actually sent, it ends in .avif, and the program, upload form or print shop you
wanted to use says it doesn't recognise the file.
Converting to JPG is the fix that works everywhere. The question is what the conversion quietly changes, because an AVIF can hold things a JPG can't: transparency, more than one frame, colours outside the standard range, HDR brightness. Most converters handle these without telling you. This one reads the file first and writes a short note under each result whenever something had to change.
What we measured
We made test AVIFs for each case and converted them in Chrome 154 on 12 October 2026, then opened the results with an independent decoder (Pillow and libavif) to check the numbers.
| Test file | What a plain converter does | What this tool does |
|---|---|---|
| Phone photo, 2048 × 1536, 497 KB | JPG at a fixed quality | 1.09 MB JPG at 92% (2.2× the AVIF), PSNR 41.1 dB against the AVIF |
| Display P3 colour test (10-bit) | Draws it as sRGB: the reddest red shifts by 6.8 Delta E, the greenest green by 5.3 | Keeps the P3 values and embeds the Display P3 profile |
| Logo with a transparent background | Usually white, sometimes black, without asking | The colour you pick, with a note |
| Animated AVIF, 12 frames | Saves the first frame silently | Saves the first frame and says it had 12 |
| HDR photo (PQ), patches at 100 to 1,000 nits | Chrome tone-maps it: 100 nits → 137, 203 → 187, 400 → 224, 1,000 → 255; the tool says so | |
Vivid colours: the difference you might actually see
Newer phones, Macs and some editing apps save AVIFs in Display P3, a colour range about a quarter larger than the sRGB range most images use. Draw such a picture onto an ordinary (sRGB) canvas, which is what a typical browser converter does, and every colour outside sRGB is pulled to its nearest edge. In our test the most saturated P3 red lost 22% of its colourfulness and the greenest green 24%. A Delta E of 6.8 is a plainly visible step; for comparison, a skin tone in the same file moved by 0.4, which nobody can see. So the loss shows up in flowers, sunsets, sports kits and brand colours, not in portraits.
This tool reads the colour information in the AVIF before converting. If the file is wide-colour, it draws it on a Display P3 canvas and the JPG carries a Display P3 profile, which current Windows, macOS, phone galleries, browsers and Photoshop all read. If an older program or a print service shows the colours wrongly, convert again with Standard sRGB: the vivid colours are toned down slightly, and the file then looks the same everywhere. Ordinary sRGB AVIFs are converted as sRGB either way, so nothing changes for them.
File size: the JPG will be bigger
Expect the JPG to be two to three times the size of the AVIF; ours went from 497 KB to 1.09 MB at 92% quality. That isn't the converter wasting space, it's the gap between a 1990s format and a 2019 one. The Smaller file and Smallest settings trade some detail for size, or if a form has a size limit, convert at 92% and then use compress image to a target size, which hits a number in KB exactly.
Transparency, animation and HDR
JPG has no transparency, so see-through areas are filled with the colour you choose, white by default. For a logo or a cut-out product photo you want to keep transparent, use AVIF to PNG instead. JPG also holds a single picture: an animated AVIF is reduced to its first frame, and the note tells you how many frames there were. AVIF to PNG can save every frame.
HDR AVIFs store brightness far above what a normal image can show. Neither JPG nor PNG has room for it, so the browser compresses the highlights into the normal range. In our test a 1,000-nit highlight became pure white while 400 nits stayed just below it, so bright areas keep some shape. The result can look flatter than on an HDR screen; that is the format, not a conversion error.
If AVIF just won't open on your computer
Converting is the quick way, but you can also teach the computer to open AVIF. Recent macOS versions open it in Preview and Photos. On Windows 10 and 11 the Photos app needs the free AV1 Video Extension from the Microsoft Store. Our guide how to open AVIF files goes through Windows, Mac, phones and Photoshop, and which route keeps the most quality. Other formats from the web have the same problem: WebP to JPG, JFIF to JPG.