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.
How to open 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. For a step-by-step walkthrough, see how to open a .avif file.
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
How to convert a .avif file
You can convert a .avif file to PNG, JPG, WebP using a conversion tool or the export menu of an app that opens it.
Convert images free: ImageConvert
.avif file signature (magic bytes)
Programs recognise a .avif file by the bytes at the start of the file, not by its name. These are the signatures for AVIF. For a full breakdown, see the AVIF file signature page.
| Hex signature | Offset | Note |
|---|---|---|
| 00 00 00 1C 66 74 79 70 61 76 69 66 | 0 | ftyp avif |
| 66 74 79 70 61 76 69 66 | 4 | 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.