.avif File Extension

What kind of file is an .avif?

An .avif file is an AV1 Image File Format image. It normally uses the image/avif MIME type. AVIF stores AV1-coded image data in a HEIF-family container, rather than as a bare AV1 bitstream. One file can hold a still image, a collection, or an image sequence.¹

AVIF supports lossy and lossless compression, alpha transparency, animation, HDR, wide color gamuts, and 8-, 10-, or 12-bit image data.² It is often a strong web-delivery choice when small files, transparency, or modern color features matter.

There is no single fixed AVIF magic number. A format-aware tool should parse the File Type Box and look for compatible brands such as avif or avis. Merely finding ftyp near the start is not enough because MP4, HEIF, and related containers share that structure.¹³

How do I open an .avif on my computer?

The easiest viewer is a current web browser. Chrome, Edge, Firefox, Opera, and Safari display AVIF images, though animation support arrived later than basic still-image support in some browsers.⁴

For editing or conversion:

• Adobe Photoshop imports and exports AVIF.⁵
• GIMP imports and exports still AVIF images. Its current documentation does not claim animated AVIF support.⁶
• avifdec and avifenc from AOMedia's libavif project provide command-line decoding and encoding.⁷

On phones and tablets, current browsers can display AVIF. Support in gallery, messaging, and editing apps can vary, so use JPEG, PNG, or WebP when a specific recipient's software is unknown.

Poly support for .avif

Poly gives AVIF images thumbnails, an in-app image preview, supported metadata, visual search, and agent understanding. You can find an image by filename or appearance, and the Poly agent can reason about the rendered picture.

Words visible inside an ordinary AVIF are not indexed as document text. Animated, HDR, or multi-image content may also be represented by a rendered still in thumbnails and agent views. Review EXIF and location metadata before sharing personal images.

History of .avif

The Alliance for Open Media published AVIF 1.0.0 in February 2019.⁸ IANA registered image/avif in January 2021.³ AVIF 1.2.0 became an AOM final deliverable in October 2025.⁹

The format builds on the royalty-free AV1 video codec but adds image-oriented container rules and interoperability profiles. Those profiles constrain details such as bit depth and dimensions so software can state realistic decoding capabilities.¹

Working with .avif and alternatives

Choose the output format for the next use, not only for the smallest file:

AVIF often needs fewer bytes than JPEG or WebP at a similar visual-quality target, but results depend on the encoder, source image, metric, and settings. Compare decoded outputs from the same source. Keep the original AVIF when it contains HDR, animation, depth, or auxiliary images that a single-frame conversion could discard.