What is AVIF in plain English?

AVIF is an image format that stores a picture using the AV1 video codec. Roughly speaking, it is a single freeze-frame from a modern video, wrapped in a file with the .avif extension. Thanks to the advanced compression borrowed from video, it fits the same photo into a file about half the size of JPEG at comparable quality.

Why is AVIF better than JPEG and WebP?

At the same visual quality AVIF is typically about 50% smaller than JPEG and 20–30% smaller than WebP. On top of that, AVIF can do things JPEG never could: 10- and 12-bit color, HDR, a wide color gamut, transparency and animation.

Do all browsers open AVIF?

Almost all modern ones: Chrome has supported AVIF since 2020, Firefox since 2021, and Safari since version 16.4 (2023). Together that is roughly 93–95% of users. Older browsers and many desktop apps (Word, Outlook, some viewers) still cannot open AVIF.

Why is AVIF slow to save?

AV1 encoding is more complex than JPEG, so creating an AVIF file takes noticeably more CPU time. Decoding (opening a finished file) is fast, however, and the file is tiny. For the web this is a great trade: you encode once and serve the image to millions of visitors.

How do I open AVIF if my program does not support it?

The easiest fix is to convert AVIF into a familiar format. For compatibility with any program use AVIF → JPG; for transparency use AVIF → PNG. You can do it online in the FormatZ converter, with no software or plugins to install.

What Is AVIF? The Next-Gen Image Format Built on AV1

You opened a website, downloaded an image, and it has an odd extension — .avif — that your usual program refuses to display. It is not an error or a virus, but one of the most efficient image formats around today. Let's unpack how a video frame became a photo half the weight of JPEG, and why the web is slowly switching to AVIF.

What AVIF is in plain English

AVIF (AV1 Image File Format) is an image format that stores a picture using the AV1 video codec. The idea is as simple as it is clever: modern video codecs have learned to squeeze frames down to a tiny size with almost no visible loss — so why not take one of those frames and save it as an ordinary photo?

That is exactly what AVIF is: a single freeze-frame from AV1 video, wrapped in a file with the .avif extension. The result is that the same photo that weighs, say, 500 KB as JPEG fits into roughly 250 KB as AVIF — at the same visual quality. And it throws in everything the old JPEG never had: true 10-bit color, HDR, transparency and even animation.

In short

AVIF is "a photo compressed like video." Take one frame from the AV1 codec, put it in a container, and you get an image roughly half the weight of JPEG, with HDR and transparency. The price is slower encoding and the fact that not every program opens it yet.

Where the format came from and who backs it

AVIF is a product of the Alliance for Open Media (AOMedia), an alliance that includes Google, Netflix, Mozilla, Microsoft, Amazon, Apple, Intel and other giants. In 2018 the alliance released AV1, an open and royalty-free video codec meant to replace patent-encumbered codecs in streaming. And in 2019 the first AVIF specification appeared, built on top of it.

The key words here are open and royalty-free. Unlike formats such as HEIC (also "a video frame," but based on the patented H.265 codec), AVIF requires no licensing fees. That is why it slotted so easily into browsers and server software: neither Google nor Mozilla has to pay for every image they render.

A grid of colorful images on a screen — AVIF is designed for rich photos and galleries — Photo galleries and catalogues are AVIF's home turf: lots of images, and every saved kilobyte matters. Photo: Pexels

Why AVIF compresses so hard

JPEG was born in 1992 and uses a relatively simple transform (DCT) with fixed 8×8-pixel blocks. AV1 is a 2018 codec, and algorithms have come a long way in the intervening decades. Here is what it does differently:

Flexible blocks. Instead of rigid 8×8 squares, the codec splits the image into blocks of varying sizes — large ones in smooth areas (sky, a wall) and small ones where detail is dense.
Smart prediction. AV1 "guesses" a block's contents from neighbouring pixels and stores only the difference between its prediction and reality. The better the guess, the less it has to record.
Modern entropy coding. The final data is packed more tightly than the algorithms of the JPEG era allowed.

The numbers bear this out. According to AOMedia itself and independent tests, at comparable quality AVIF saves about half the weight relative to JPEG and roughly 20–30% relative to WebP.

≈−50%vs JPEG size

≈−20–30%vs WebP size

2019format introduced

What JPEG can't do: color, HDR, transparency

Small size is only half the story. The other half is that AVIF is technically richer than any "classic" format. Here are its strengths:

Full name

AV1 Image File Format

Extension

.avif

Codec

AV1 (AOMedia)

Color depth

8 / 10 / 12 bit

Transparency

Yes (alpha)

Animation

Yes

What this means in practice:

10- and 12-bit color. JPEG stores 8 bits per channel — 256 brightness levels. AVIF reaches 1024 and beyond, so smooth gradients (sunsets, skies) don't break up into visible "steps."
HDR. The format understands the PQ and HLG transfer curves from the Rec. 2100 standard — the same ones used in HDR films. A shot from a modern smartphone can preserve the real brightness range, from deep shadows to blinding sun.
Transparency (alpha). Like PNG, but far lighter. Perfect for logos and icons on websites.
Animation. AVIF can hold short clips, replacing the heavy GIF at a fraction of the weight.

AVIF is not just "a smaller JPEG." It is a format that brings cinematic color and HDR into an ordinary picture.

Downsides and gotchas

To keep this honest, let's name the weak spots too — AVIF has two, and both matter.

Keep in mind

Slow encoding. Compressing a photo into AVIF is harder than into JPEG and burns noticeably more CPU time. For the web that is no problem (encode once, serve everyone), but batch-converting thousands of photos on a weak laptop is tedious.

Incomplete support. Browsers are largely on board (~93–95% of users), but many desktop apps — Microsoft Word, Outlook, some viewers and older Photoshop versions — still don't open AVIF.

That second problem gave rise to a simple strategy for websites: serve AVIF to those who understand it and automatically fall back to WebP or JPG for everyone else. There is more on this in our article AVIF for website speed.

Where you already meet AVIF

Chances are you have seen AVIF without noticing — the browser quietly serves the right format. Today AVIF is used by:

Large sites and social networks. Netflix, YouTube (thumbnails), online stores and news portals serve images in AVIF to make pages load faster.
Smartphones. Modern Android devices can shoot and save photos straight to AVIF, saving space in the gallery.
Web development. The <picture> tag lets you specify AVIF as the primary option and JPG as the fallback.

A photo-gallery website on a laptop screen — images on such pages are often served as AVIF — The more images on a page, the more obvious AVIF's loading-speed advantage becomes. Photo: Pexels

How to open and convert AVIF

If your browser opens AVIF but a program on your computer doesn't, don't rush to hunt for plugins. The fastest route is to convert the file into a familiar format:

Upload the AVIF

Drag your .avif into an online converter — nothing to install.

Pick a format

JPG for maximum compatibility, PNG if transparency matters.

Download the result

The finished file opens in any program on any device.

AVIF won't open? Convert it in seconds

The free FormatZ converter turns AVIF into a universal JPG right in your browser — no install, no sign-up, no plugins.

Convert AVIF to JPG

If you need to keep transparency, use the AVIF to PNG converter. And to compress your own photos into AVIF instead, try JPG to AVIF. The full list of conversions is on the all formats page.