What is a .avif file?
AV1 Image File Format · Image · Alliance for Open Media · 2019
AVIF is a next-generation image format based on the AV1 video codec. It typically produces the smallest files of any common format at a given quality, with support for transparency, HDR and wide colour, which is why it is spreading fast on the web.
What is a .avif file used for?
AVIF uses the same compression engine as AV1 video, so it squeezes photos far harder than JPEG and often beats WebP too. A well-encoded AVIF can be a fraction of the size of the JPEG it replaces.
Beyond size, AVIF supports 10 and 12-bit colour, HDR and transparency, making it a strong choice for high-quality photography on the web.
Support is now broad in browsers, but desktop apps lag behind. Encoding can also be slower than JPEG, so it is most common on sites that optimise images ahead of time.
What opens a .avif file?
The .avif format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- Photos (with AV1 Video Extension)
- Chrome and Edge
- GIMP 2.10+
macOS
- Preview (macOS 13+)
- Safari 16+
- GIMP
Linux
- GIMP
- Firefox
- ImageMagick (with libavif)
Web
- Most current browsers
Open a .avif file step by step
- Confirm the file really is a .avif. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with Photos (with AV1 Video Extension) or Chrome and Edge.
- On Mac, use Preview (macOS 13+) or Safari 16+.
- On Linux, try GIMP or Firefox.
- Still stuck? Convert the .avif to PNG, which opens more widely.
Why can't I open my .avif file?
Almost always because no installed app understands AVIF. Install one of the apps above, or convert the file to a format your existing software already reads. If double-clicking opens the wrong program instead of nothing at all, the file association is set to the wrong app rather than the file being broken.
The other possibility is that the file is not really a .avif at all. Drop it into the file identifier to check it by its bytes instead of its name. Nothing is uploaded.
How to convert a .avif file
You can convert a .avif file to PNG, JPG, WebP.
GIMP 2.10.30 and later exports AVIF through File then Export As; ImageMagick does it in one line with magick in.avif out.png. Converting to JPG throws away the HDR range and the 10-bit colour that AVIF was chosen for in the first place.
Convert images free: ImageConvert
What is the .avif file signature (magic bytes)?
A .avif file starts with the hex bytes 00 00 00 1C 66 74 79 70 61 76 69 66, which read as ....ftypavif in ASCII. Programs identify AVIF by those bytes, not by the filename, so a renamed file still gives itself away.
These are the documented signatures for AVIF. For a full breakdown, see the AVIF file signature page.
| Hex signature | Offset | ASCII | Note |
|---|---|---|---|
| 00 00 00 1C 66 74 79 70 61 76 69 66 | 0 | ....ftypavif | ftyp avif |
| 66 74 79 70 61 76 69 66 | 4 | ftypavif | ftyp box, brand 'avif' |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .avif file?
AVIF is a next-generation image format based on the AV1 video codec. It typically produces the smallest files of any common format at a given quality, with support for transparency, HDR and wide colour, which is why it is spreading fast on the web.
Is AVIF smaller than WebP?
Usually yes, especially for photos at low to medium quality. The gap narrows for simple graphics, and AVIF takes longer to encode.
Why won't my photo editor open an AVIF?
Many editors added AVIF only recently. Update the app, or convert the file to PNG or JPG first.