What Is an AVIF File? The New Image Format Explained
· 5 min read · Vision
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An AVIF file is an image compressed with the AV1 video codec — the same royalty-free codec behind modern video streaming — wrapped in a container derived from HEIF. If you've just met your first AVIF file, it almost certainly came from a website: AVIF is the newest of the web image formats and typically produces the smallest files of them all, at the price of patchier support in desktop software.
What is an AVIF file under the hood?
AVIF stands for AV1 Image File Format. It was specified by the Alliance for Open Media — the industry group behind AV1, whose members include Google, Mozilla, Netflix, Amazon and Apple — with the spec finalized in 2019. Two design goals explain everything about it:
- Compress harder than anything before it. AV1's intra-frame coding applied to stills produces noticeably smaller files than JPEG and WebP at comparable quality, especially at aggressive compression levels where JPEG falls apart into blocks.
- Stay royalty-free. HEIC has comparable technical chops but sits on patented HEVC, which is why browsers never adopted it. AVIF delivers the same class of compression without licensing fees — so browsers did adopt it.
Feature-wise it's the most complete of the web formats: lossy and lossless modes, alpha transparency, animation, wide color gamut, and 10/12-bit HDR — the only mainstream web image format that can carry HDR photos properly.
The trade-off is encoding speed: producing an AVIF takes distinctly longer than a JPEG or WebP. For a website build pipeline that's a one-time cost; for quick interactive exports it's why WebP hasn't disappeared.
Where you'll run into AVIF files
- Saved images from large websites — image CDNs increasingly serve AVIF to supporting browsers, so "Save image as…" hands you an
.avif. - Modern site build pipelines — frameworks and image services generate AVIF variants automatically.
- HDR photo exports — tools that need to hand off HDR stills in a web-ready format.
- Wallpaper and asset packs — distributors chasing the smallest download sizes.
How to open AVIF files
Any browser
The universal answer: drag the file into a browser tab. Chrome, Firefox, Edge and Safari all render AVIF — support landed across them between 2020 and 2022, so anything current works.
Windows 11
The Photos app opens AVIF once the free AV1 Video Extension from the Microsoft Store is installed — the image data inside is AV1, so the codec does the work. No extension, no preview; the browser route needs nothing.
macOS
Recent macOS versions open AVIF in Preview and Quick Look. On older systems that predate support, use the browser or convert.
iPhone, iPad and Android
Current iOS and Android versions display AVIF in their photo apps and browsers. Older devices are hit-and-miss — if a recipient can't open one, send JPG instead.
Editors
This is where AVIF still lags: many photo editors either lack AVIF support or gained it only recently. If your editor refuses the file, convert to PNG and edit that.
AVIF vs WebP, JPG and HEIC
| AVIF | WebP | JPG | HEIC | |
|---|---|---|---|---|
| Compression | AV1-based, strongest | VP8-based, strong | Baseline | HEVC-based, strong |
| Transparency | Yes | Yes | No | Yes |
| HDR / >8-bit | Yes | No | No | Yes |
| Animation | Yes | Yes | No | Sequences |
| Licensing | Royalty-free | Royalty-free | Free | Patented (HEVC) |
| Browser support | All modern | All modern | All | Safari only |
| Best for | Smallest web images, HDR on the web | Fast general web images | Universal sharing | Apple camera storage |
When should you convert AVIF (and to what)?
- A program or upload form rejects it → AVIF to JPG — the compatibility answer.
- You need transparency or a lossless editing copy → AVIF to PNG.
- You want broad web-format compatibility with small files → AVIF to WebP.
- A folder of mixed saves → the AVIF converter for batches.
Converting to AVIF is worth it in one main case: images on a website you control, where the encode time is paid once and every visitor benefits.
Common problems and fixes
Windows Photos won't open it. Install the AV1 Video Extension from the Microsoft Store, or open the file in a browser, or convert to JPG.
Your photo editor doesn't recognize it. AVIF support in editors trails browsers by years. Convert to PNG for lossless editing; report back to your editor's feature tracker.
The image looks different after converting to JPG. If the AVIF carried HDR or wide-gamut color, JPG can't represent it — highlights get compressed into the 8-bit range. That's a format limitation, not a converter bug.
Uploading fails with "unsupported image". Same story as WebP a few years ago: allowlists lag reality. Convert to JPG or PNG before uploading.
Encoding your own AVIFs is slow. Normal. Use it in build pipelines where it runs once, not in interactive workflows where you wait on every save.
FAQ
Why did my downloaded image save as AVIF? The website served AVIF to your browser because it supports it, and the browser saved exactly what it received. It's the site's choice, not a setting on your side. Convert the file if you need it in another format.
Is AVIF better than WebP? On compression and features, yes — smaller files and real HDR support. WebP still wins on encode speed and on support in non-browser software. For a website, serving AVIF with a WebP or JPEG fallback is the common pattern.
Is AVIF the same thing as HEIC? They're cousins: both pack a video codec's still-image mode into a HEIF-style container. The decisive difference is licensing — AVIF's AV1 codec is royalty-free, so every browser ships it; HEIC's HEVC isn't, so they don't.
Does AVIF lose quality? Its lossy mode does, like JPEG and WebP — it just loses less at the same file size. There's also a lossless mode, though at lossless sizes PNG is often the more practical choice for compatibility.
Can I set my camera or phone to shoot AVIF? Phones don't shoot AVIF today — iPhones save HEIC or JPEG, most Androids save JPEG. AVIF files are made, not captured: exported by software or generated by websites from other source formats.