What is an AVIF file, and how do you open or convert it on Windows?

What AVIF is

You did nothing wrong: the file is a real image, in a format most of your programs have never met. AVIF stands for AV1 Image File Format. AV1 is the royalty-free video codec that the Alliance for Open Media (Google, Netflix, Apple, Microsoft, Mozilla, Amazon and others) published to replace patented codecs in streaming video. AVIF takes a single AV1 frame, or a sequence of them, and wraps it in the HEIF container, the same container Apple uses for HEIC photos. The format was first released in 2019 and the file extension is .avif, with the MIME type image/avif.

Because it borrows a video codec, AVIF has features that older image formats do not: lossy or lossless compression, a transparency channel, animation, 8-, 10- or 12-bit colour, HDR and wide colour gamuts, and image dimensions limited only by a 31-bit counter. MDN’s image format guide puts lossy AVIF at around 50 percent smaller than JPEG for the same visual quality, against 25 to 35 percent for WebP. The cost is that encoding an AVIF takes far more CPU time than encoding a JPG, and that it cannot render progressively while it loads. Format facts here come from the Alliance for Open Media and MDN’s image format guide; Store facts from Microsoft’s listings, 23 October 2026.

Why websites keep giving you AVIF

When a browser asks for an image it tells the server which formats it accepts. News sites, shops and image CDNs keep several versions of every picture and send the smallest one the browser can show. Chrome has accepted AVIF since version 85, Firefox since 93, Safari since 16.1 and Edge since 121, so for almost everyone the smallest version is now AVIF. Right-click, Save image as, and the file that lands in Downloads is .avif, even when the address on the page ended in .jpg.

That is fine inside the browser. The trouble starts when the image has to go somewhere else: an older Photoshop, a Word document, a print shop’s upload box, a forum, a CRM, a PowerPoint on a colleague’s laptop. Those expect JPG or PNG, and a folder of collected reference images becomes unusable until it is converted.

AVIF vs WebP vs JPG

The pattern is simple. AVIF is the best format for delivering a picture to a browser and the worst for handing one to anything else. JPG is the opposite. WebP sits in between, and most of the same advice applies to it; see how to save a WebP image as JPG.

How to open an AVIF file on Windows 10 and 11

• In a browser: drag the file into Chrome, Edge or Firefox. This always works and needs nothing installed.
• In Photos: install two free Microsoft Store packages, HEIF Image Extension and AV1 Video Extension. Microsoft’s own listing for the HEIF extension says the AV1 package must be installed to view images stored in HEIF files that use the .avif extension. After that Photos, and the Explorer preview pane, show AVIF.
• In everything else: convert it. Older image editors, Office versions, print services and most upload forms do not know the format, and no extension changes that.

How to convert AVIF to JPG or PNG on Windows

Drop the .avif files on PlainJPG and they come out as JPG or PNG, usable in every program you own, with nothing uploaded. PlainJPG is a $15 Windows app that converts whole folders of HEIC, WebP and AVIF to JPG or PNG on the PC, keeps EXIF and file dates, nothing uploaded. Its AV1 decoder (dav1d) is built in, so it converts AVIF on any Windows 10 or 11 PC without the Store extensions. The first 25 images are free; after that it is $15 once for 2 PCs.

1. 1

   Install PlainJPG

   From the free download (Windows 10 version 2004 or later and Windows 11, x64 and ARM64).

2. 2

   Drop the .avif files or their folder

   Drag them onto the PlainJPG window, or right-click an .avif in File Explorer and choose Convert to JPG with PlainJPG.

3. 3

   Pick the output

   JPG for photos (quality 92 by default), PNG for logos and cut-outs with transparency, or Auto, which writes PNG only for images with transparent pixels.

4. 4

   Click Convert

   The copies land next to the originals with the same names and dates; any EXIF or XMP the AVIF carried is written into them.

Two free alternatives for a single file: open the AVIF in a browser, right-click, Copy image, paste into Paint and save as JPEG picture; or, if you use the command line, ImageMagick’s Windows build includes the aom library and converts with magick picture.avif picture.jpg. Both are one file at a time and neither copies the file’s dates. The full guide, with what the JPG keeps, is on the AVIF to JPG page; a licence is $15 once for two PCs.

Does converting AVIF to JPG lose quality?

An AVIF saved from a website is almost always lossy already, so there is no perfect original to get back. A converter decodes the pixels once and writes them as JPG at the quality you choose; at PlainJPG’s default of 92 the difference is invisible for photographs, and PNG is lossless if the image is a graphic. The JPG will be larger than the AVIF, often two or three times larger, which is not a fault: AVIF simply packs pixels tighter, and that is the whole reason websites use it. The pixel count never changes.