AVIF files: the newest image format, and the software that cannot read it

Where AVIF came from, how much smaller it really is, and what to convert it to when a tool refuses it. Convert AVIF in your browser, no upload.

At a glance

Type: Image
Extensions: .avif
MIME type: image/avif

AVIF is a still image wrapped in the machinery of a video codec: an AV1 keyframe stored in a HEIF container. AV1 came out of the Alliance for Open Media in 2018 as a royalty-free competitor to HEVC, and using its intra-frame coding for photographs turns out to beat everything that came before — typically 20–30% smaller than WebP at the same quality, which puts it far ahead of JPEG.

It also supports what JPEG never could: an alpha channel, high dynamic range, wide colour gamuts and 10- or 12-bit depth. For a format whose files are smaller than a JPEG, that is a remarkable combination, and it is why sites that care about page weight have started serving AVIF to browsers that accept it.

Which is where the trouble starts. Browsers decode AVIF — Chrome, Firefox and Safari all do — but a great deal of other software does not: image editors, office suites, print workflows, older phones, upload forms. Right-clicking to save an image from a modern site and receiving a file nothing local will open has become an ordinary experience, and converting out of AVIF is the fix.

Note the asymmetry in what a browser can do. It can decode AVIF but cannot encode it, so conversions out of AVIF work here and conversions into it are marked unavailable rather than shipped broken. When choosing a target: JPG for a photograph that needs to open anywhere, PNG when there is transparency to keep or you are about to edit — and expect either to be considerably larger than the AVIF was.

Convert AVIF to other formats

FAQ

Why can I not open my AVIF file?

Because it is a recent format. Browsers decode it, but many image editors, office applications, print workflows and older devices have not implemented it.

Is AVIF really better than WebP and JPEG?

Yes, on compression — typically 20–30% smaller than WebP at the same quality and far ahead of JPEG. It also supports transparency, HDR and wide colour, which JPEG does not.

Can I convert an image to AVIF here?

Not yet. Browsers can decode AVIF but not encode it, and this site uses the browser's own codecs. That direction is marked unavailable rather than shipped as something that fails.

AVIF to JPG or to PNG?

JPG for photographs that need to open anywhere. PNG when the image has transparency or you are about to edit it. The PNG will be dramatically larger, since AVIF is the most efficient format here and PNG one of the least.

Will the converted file be bigger?

Almost certainly, and considerably. AVIF is far more efficient, so matching its quality in an older format takes more data. You are converting for compatibility, not for size.

Does AVIF support transparency?

Yes, a full alpha channel. That is why PNG rather than JPG is the right target when the image is a logo or a cut-out.

Is AVIF lossy or lossless?

It has both modes, and most AVIF files on the web are lossy. Converting one to PNG therefore stops further loss but cannot undo what has already been discarded.

What about HEIC — is that the same thing?

Related but not the same. HEIC is HEVC in the same HEIF container, and is what iPhones produce. Browsers do not decode HEIC, which is why those conversions are not available here while AVIF ones are.