What Is AVIF? The Image Format Explained

A video codec, repurposed for photos. Here is what AVIF actually is, how it compresses images so efficiently, what it can do that JPEG cannot, and why you keep seeing .avif files in 2026.

Daniel Osei·June 26, 2026·11 min read

You downloaded a photo, or your phone exported one, and it ended up with a .avif extension instead of the familiar .jpg. Maybe it opened fine. Maybe it did not open at all, depending on what you tried to open it with. Either way, the natural question is simply: what is this, and why does it exist?

AVIF stands for AV1 Image File Format. It is a still image format that borrows its compression engine from video technology, and in 2026 it has become one of the most widely used image formats on the web, sitting right behind JPEG and WebP in terms of how often you will actually encounter it. This guide explains what AVIF actually is, how it manages to produce such small files, what makes it different from the formats you already know, and where it shows up in practice.

Where AVIF Came From

AVIF was released in 2019 by the Alliance for Open Media, a consortium of major technology companies including Google, Apple, Netflix, Amazon, Microsoft, Mozilla, and Cisco. These are, not coincidentally, among the companies that pay the most in bandwidth costs and have the most to gain from images that are smaller without looking worse.

The format takes the AV1 video codec, the same compression technology behind efficient 4K and 8K video streaming on services like YouTube and Netflix, and applies it to single still images instead of moving video. This is a genuinely unusual approach: a video codec, repurposed for photos. It works because video codecs are built to compress complex visual detail extremely efficiently, frame by frame, and a single photo is essentially one frame of that same problem.

AVIF is open and royalty-free, meaning no company has to pay a licensing fee to use it, encode it, or build software that supports it. This distinguishes it from HEIC, Apple's similar-sounding format, which is built on HEVC, a codec that does carry licensing costs. That difference in licensing is a major reason browsers were willing to adopt AVIF quickly while some software has been slower to add full HEIC support outside Apple's own ecosystem.

How AVIF Actually Compresses an Image

Understanding why AVIF files are so much smaller than JPEG requires a quick look at what each format is actually doing under the hood, because the difference is not a minor tweak, it is a fundamentally more sophisticated approach.

JPEG, designed in 1992, divides every image into fixed 8 by 8 pixel blocks and compresses each one using the same basic method regardless of what is actually in that block. A block containing a smooth blue sky and a block containing fine hair detail get treated almost identically. This rigidity is exactly why JPEG produces visible blocky artifacts when pushed to smaller file sizes.

AVIF works in a fundamentally more flexible way. It divides the image into blocks ranging from 4 by 4 pixels up to 128 by 128 pixels, choosing the size based on what is actually in that part of the image. A large, smooth area like a clear sky gets one big efficient block. A detailed area like hair or text gets broken into many small blocks so the fine detail is preserved. For each block, the encoder looks at over 50 directional prediction modes, essentially different ways of guessing what the block should look like based on the blocks around it, and picks whichever prediction comes closest to the real thing. Instead of storing the actual pixel data, it stores only the difference between the prediction and reality, which is a much smaller amount of information to encode.

After that prediction step, AVIF applies an in-loop filtering process that smooths out compression artifacts before the image is even finished encoding, which is part of why AVIF tends to degrade more gracefully than JPEG at aggressive compression settings: instead of obvious blocky edges, you tend to see a softer, less objectionable loss of fine detail.

One particularly clever AVIF feature is called film grain synthesis. Photographic grain and digital noise are expensive to compress because they look random, and compressing genuine randomness efficiently is difficult for any codec. AVIF's encoder can instead detect grain, strip it out before compressing the smooth underlying image, and then mathematically regenerate similar-looking grain back into the image after decoding. The visual texture is preserved without ever having to compress the actual noisy data, which saves a meaningful amount of file size on grainy or noisy photos specifically.

What AVIF Can Do That JPEG Cannot

Beyond raw compression efficiency, AVIF supports several capabilities that simply do not exist in JPEG at all.

Transparency is fully supported through an alpha channel, the same capability that makes PNG and WebP useful for logos and graphics with see-through backgrounds. JPEG has no mechanism for this whatsoever.

HDR and wide color gamut support is a genuine technical leap. JPEG is limited to 8-bit color, meaning 256 possible brightness levels per color channel, which adds up to about 16.7 million total representable colors. AVIF supports 10-bit and 12-bit color, which works out to roughly 68.7 billion possible colors, a difference of more than 4,000 times the range. In practical terms, this means AVIF can store and display the kind of high dynamic range photography modern smartphones (particularly iPhone Pro models) are increasingly capable of capturing, without the banding or stepped gradients that 8-bit JPEG produces in smooth skies, sunsets, or any subtle color transition.

Lossless compression is available as an option, alongside the more commonly used lossy mode. JPEG is lossy only; it has no lossless mode at all.

Animation is supported as well, through stored image sequences, which makes AVIF a legitimate replacement for animated GIF in contexts where smaller file size and better quality both matter.

How Much Smaller Are AVIF Files, Really

The numbers vary somewhat depending on which source you check and what kind of image is being tested, but the pattern across independent benchmarks is consistent. At equivalent visual quality, AVIF files typically run 40 to 60% smaller than JPEG and roughly 20 to 30% smaller than WebP.

To put that in concrete terms drawn from representative testing: a photograph that looks comparable across formats might land around 550KB as JPEG, 400KB as WebP, and 300KB as AVIF. A logo with transparency might be 45KB as PNG, 30KB as WebP lossless, and 22KB as AVIF lossless. The pattern holds across image types, even though the exact percentages shift depending on what is actually in the photo. Gradients, skin tones, and fine natural texture tend to be where AVIF's advantage over both JPEG and WebP is most pronounced.

It is worth being precise about the framing here too: at the same file size, AVIF produces a visibly better-looking image than JPEG. At the same visual quality, AVIF produces a meaningfully smaller file. Those are two ways of describing the same underlying advantage, and which framing matters more depends on whether you are optimizing for a strict size budget or for the best possible appearance within reasonable limits.

Why Encoding AVIF Takes Longer

There is a real tradeoff behind all of this efficiency, and it shows up specifically during encoding, not during viewing.

Choosing the best block size from a range of options, testing over 50 directional prediction modes per block, and running in-loop filtering all require considerably more computation than JPEG's comparatively simple, fixed approach. The practical result is that encoding a single image as AVIF can take noticeably longer than encoding the same image as JPEG or WebP, sometimes by a wide margin at the highest quality and largest resolution settings.

This matters far more for the systems creating AVIF files than for anyone simply viewing them. A photo viewer or web browser decoding an AVIF file to display it on screen does not experience meaningful delay; decoding is fast on essentially all modern hardware. The slowdown specifically affects services that need to generate AVIF files on demand, in real time, for every request. For a website or app that converts and stores images once and then serves that same pre-converted file to every subsequent visitor, the one-time encoding cost is a complete non-issue.

Opening and Viewing AVIF Files

If you have received an AVIF file and need to view it, the path depends on what device and software you are using.

On a current version of Windows 11, Photos and File Explorer display AVIF thumbnails and open the files natively with no extra installation needed. Windows 10 requires installing the free AV1 Video Extension from the Microsoft Store first, after which thumbnails and viewing work the same way.

On macOS, Ventura (version 13) and later versions support AVIF directly in Preview and Quick Look, so double-clicking or pressing the space bar on a selected file works exactly as it would with any other image.

Every modern browser, meaning current versions of Chrome, Firefox, Safari, and Edge, will display an AVIF file directly if you drag it into a browser tab or open it as a URL, which is a reliable fallback regardless of what operating system you are running.

For editing rather than just viewing, Adobe Photoshop added AVIF support starting with version 23.2 in 2022, with full open, edit, and save support arriving in the 2025 release. GIMP, Affinity Photo, and Figma all support AVIF natively as well at this point.

Why You Are Seeing More AVIF Files in 2026

Browser support reaching roughly 93 to 94% of users globally is the single biggest reason AVIF has moved from "interesting new format" to something you genuinely encounter in everyday browsing. Chrome added support in 2020, Firefox in 2021, and Safari in 2022 with version 16, which was the last major holdout. By 2026, current versions of every major browser support it by default.

That browser support threshold is what unlocked widespread adoption among large platforms, since serving a format only a fraction of visitors can actually view is not a viable choice for any major site. Several large platforms have adopted AVIF specifically for image-heavy, performance-sensitive contexts: thumbnail images on streaming services, product photography on large e-commerce platforms, and increasingly as a default delivery format pushed through major CDN providers like Cloudflare and Fastly, which can automatically convert and serve AVIF to browsers that support it without the site owner needing to do anything beyond enabling the feature.

AVIF Versus the Formats You Already Know

If you are weighing AVIF against JPEG specifically, including the technical comparison, where each one wins, and how to decide between them for a real project, the full AVIF versus JPG comparison covers that decision in depth.

If you are deciding between AVIF and WebP, the practically more common choice for most websites today, the WebP versus AVIF comparison walks through encoding speed, tooling support, and the size difference between the two modern formats specifically.

For the full picture across every format currently in active use, not just AVIF against one other option, the complete guide to image formats covers JPEG, PNG, WebP, AVIF, GIF, SVG, HEIC, TIFF, BMP, and JPEG XL together in one place, with a practical decision table at the end.

Converting To and From AVIF

If you need to convert an existing JPEG or PNG into AVIF to take advantage of the smaller file size, the JPG to AVIF converter and PNG to AVIF converter handle this directly in your browser, with nothing uploaded to a server in the process.

If you have received an AVIF file and need it in a more universally compatible format, for an email attachment, an older piece of software, or any upload form that has not been updated to accept AVIF, the AVIF to JPG converter and AVIF to PNG converter convert it back in seconds.

Summary

AVIF is a modern image format built on video compression technology, producing files roughly 40 to 60% smaller than JPEG and 20 to 30% smaller than WebP at comparable visual quality, while also supporting transparency, HDR, wide color gamut, and animation in ways JPEG simply cannot. It is open, royalty-free, and as of 2026 is supported by the vast majority of browsers and operating systems in active use.

The honest tradeoff is encoding speed, not viewing speed: creating an AVIF file takes longer than creating the equivalent JPEG or WebP, but opening and viewing one is fast everywhere modern software runs. For anyone simply trying to make their photos smaller without a visible quality drop, AVIF is, as of 2026, one of the strongest available options, and converting to it takes seconds using a browser-based tool that needs no installation at all.

Written by

Daniel Osei

Web Performance Engineer

Daniel has spent 6 years optimizing images and web assets for publishers and e-commerce brands. He writes about image formats, compression techniques, and web performance at ImgTweak.