What is AVIF? The newest image format, and when to convert it

AVIF is an image format that stores pictures using the compression from AV1, a modern video codec, and it is the reason an image saved from a shopping site or a news page now sometimes arrives as a .avif file. It makes smaller files than JPG, PNG and usually WebP for the same visible quality, it supports transparency, and every current browser can show it. What is AVIF not good at? Being opened by older desktop apps, which is the moment most people first meet it.

This guide explains what AVIF is and where it came from, how it compares with JPG, PNG and WebP, which browsers, systems and apps read it (checked 16 September 2026), how its transparency works, and when converting an AVIF to PNG or JPG is worth doing.

What is AVIF, exactly?

AVIF stands for AV1 Image File Format. It is published by the Alliance for Open Media, a group formed in 2015 by companies including Google, Mozilla, Microsoft, Amazon and Netflix, and later joined by Apple, to build video compression anyone could use without paying patent royalties. Their video codec, AV1, is what YouTube and Netflix use for much of their streaming. AVIF takes a single compressed AV1 frame and puts it in a HEIF container, the same kind of box an iPhone’s HEIC photo uses. Version 1.0 of the specification was published in 2019.

So AVIF and HEIC are close relatives: same container idea, different compression inside. The difference that matters is licensing. HEIC’s HEVC compression carries patent fees, which is why Chrome, Edge and Firefox never adopted it; AV1 was designed to be royalty free, which is why they all adopted AVIF. What is a HEIC file covers the iPhone side of that story.

The Alliance for Open Media’s own page on the format claims files more than 50 percent smaller than JPEG and more than 30 percent smaller than WebP. Those are the maker’s figures on its chosen test images; on real photos at quality settings you would actually use, a saving of roughly a third to a half against a well-made JPG is a fair expectation.

What AVIF can store

• Lossy and lossless compression. Almost every AVIF on the web is lossy, because that is where the savings are. Lossless AVIF exists but is often no smaller than a good PNG.
• Transparency. A full alpha channel with soft edges, compressed separately from the colour.
• More than 8 bits per channel. 10 and 12 bit colour, which means smoother gradients without banding.
• HDR and wide colour. Brighter highlights and more saturated colours on screens that can show them.
• Animation. A sequence of frames, as a much smaller alternative to an animated GIF.

The cost of all that is encoding time. Making a good AVIF takes far more processor work than making a JPG or WebP of the same picture, which is why websites usually generate them once, in advance, rather than on the fly. Viewing one is fast.

AVIF vs JPG, PNG and WebP

For photos on a web page AVIF usually gives the smallest file. At very low quality settings it degrades gracefully, smoothing detail away rather than breaking into blocks, which is why it looks better than JPG when both are squeezed hard. At high quality settings the gap narrows. WebP is the safer, faster middle ground, and PNG vs WebP for websites goes through the choice for transparent images in detail. getSVG’s WebP vs PNG vs JPG covers the three older formats side by side.

Which browsers support AVIF?

All the current ones. From caniuse.com, checked 16 September 2026:

• Chrome from version 85 (2020), and Chrome for Android.
• Firefox from version 93 (2021).
• Safari from 16.4 on Mac, with partial support from 16.1; Safari on iOS from 16.
• Edge from version 121 (2024), much later than Chrome, so older Edge versions do not show AVIF even though a Chrome of the same age did.
• Samsung Internet from version 14.

caniuse.com put global support at about 95 percent of browsers in use. The missing few percent are old iPhones that cannot update past iOS 15, old Macs stuck on older Safari, and very old Edge installs, which is why careful sites still offer a JPG or WebP fallback.

How to open an AVIF file on Windows, Mac and phones

Windows 11 and 10. The Photos app reads AVIF through Microsoft Store extensions. The HEIF Image Extension’s Store description says the AV1 Video Extension must be installed to view images in .avif files. Both were free and published by Microsoft Windows when checked in the US Microsoft Store on 16 September 2026. The simplest alternative needs no install: drag the .avif file onto an open Chrome, Edge or Firefox window and it displays.

Mac. macOS Ventura and later display AVIF in Preview and Safari. On an older Mac, open the file in Chrome or Firefox.

iPhone and iPad. iOS 16 and later display AVIF in Safari.

Android. Android’s developer documentation lists AVIF encoding and decoding as mandatory from Android 14, so recent phones open it in the gallery and in Chrome.

Editing apps and websites. This is where AVIF still trips people up. Older versions of desktop editors, office suites, some social networks’ upload forms and many print services do not accept it. When one refuses, convert.

Transparency in AVIF

An AVIF with transparency stores the alpha channel as a second, separately compressed image. That alpha image is usually compressed lossily, like the colour, which keeps files small but can very slightly soften a hard cutout edge. For a photo cutout that softening is rarely visible; for pixel-precise graphics, lossless PNG or lossless WebP is safer.

What goes wrong with AVIF transparency is usually not the format but the path it takes. An app that cannot read AVIF alpha may show black or white behind the subject, and converting to JPG always paints a colour in. What a transparent background actually is explains alpha and those failure modes, which apply to every format that has it.

How to make an AVIF file

If you run a website and want to try AVIF, you do not need special software. Squoosh, Google Chrome Labs’ free image compression web app, has an AVIF encoder built in and works on your own device.

1. Start from a good master. A PNG or a high-quality JPG at the largest size the image will be shown, not a file that has already been compressed hard.
2. Open squoosh.app and drop the picture on the page.
3. Choose AVIF in the compression settings on the right.
4. Lower the quality until you see a difference when you drag the divider across the picture, then raise it a little. AVIF’s quality numbers do not match JPG’s, so judge by eye rather than by copying a number from another format.
5. Download the result and compare its size with the original.

Encoding a large photo can take several seconds, noticeably longer than WebP; that is normal for AVIF and does not affect how quickly visitors see it. For a whole site, most platforms and image services that support AVIF generate the files for you from the images you upload, which is easier than converting each one by hand.

When to convert AVIF to PNG or JPG

Converting AVIF never improves a picture. The file gets larger, often two to five times, and looks the same. So convert only when you have a reason:

• An app or upload form refuses .avif. Convert a photo to JPG; convert anything with transparency to PNG.
• You are going to edit it. Convert to PNG first, so repeated saves do not add compression on top of compression.
• It needs to keep a transparent background in apps that do not read AVIF. PNG is the format everything reads with transparency intact.
• You are archiving. PNG and JPG will open in software decades from now with certainty; AVIF very probably will, but it is young.

For your own website, do the opposite: keep a PNG or high-quality JPG as the master and publish AVIF or WebP from it. WordPress, for example, has accepted AVIF uploads since version 6.5, provided the server’s image library supports the format.

On a computer, the no-upload way to convert is to open the AVIF in something that reads it and export: Preview on a recent Mac exports to PNG or JPEG, and Squoosh, Google’s image compression web app, converts in the browser tab without sending the image to a server, according to its own documentation. Many online AVIF converters upload the file instead; how to check a website is not uploading your photos shows how to tell the difference yourself.

Questions

Is AVIF better than WebP?

For file size, usually yes: AVIF typically makes smaller files than WebP at the same visible quality, especially for photos. WebP encodes much faster and is supported by slightly more browsers and apps. Many sites serve AVIF with WebP or JPG as a fallback.

How do I open an AVIF file on Windows?

Install the AV1 Video Extension from the Microsoft Store, which was free when checked in September 2026, together with the free HEIF Image Extension; the Store description says both are needed for .avif files. Any current web browser also opens it: drag the file onto a Chrome, Edge or Firefox window.

Does AVIF support transparency?

Yes. An AVIF can carry a full alpha channel with soft edges, like PNG and WebP. Whether the transparency survives depends on the app you open it in and the format you convert it to: JPG will lose it.

Why do images save as AVIF from websites?

Because the website sends AVIF to browsers that can read it, to make pages load faster. When you save the image, you get the file the browser received. The same page may give a JPG to an older browser.

Should I convert AVIF to PNG or JPG?

To PNG if the picture has transparency or you are going to edit it; to JPG if it is a photo you need to upload somewhere that refuses AVIF. Either way the file gets larger and looks no better, so only convert when an app needs it.

Is AVIF lossless?

It can be. AVIF supports both lossy and lossless compression, but nearly all AVIF files on the web are lossy, because that is where the big size savings are.