Open AVIF files on Windows

Check where the file came from

AVIF can come from a website, an editor export or another image workflow. Its extension does not prove the source or whether another copy exists. If a download has a misleading .jpg URL, see Chrome WebP.

If the image opens in the browser but not in a Windows app, that app may lack AVIF support. This does not prove the downloaded file is intact. A misleading .jpg download URL is covered in Chrome WebP.

Photos may open it while Explorer stays blank

These are two separate pieces of software with separate decode paths. The Photos app can pick up AV1 from a Store extension, while Explorer draws thumbnails through a shell provider and then keeps the result in a per-folder cache. So the state people report as contradictory is normal: a double-click shows the photo and the folder view shows nothing.

An upload field has its own accepted formats and size limits. Installing a local decoder does not change those rules. Convert only when the destination calls for another format, then test the copy there.

Check HEIF support and AV1 decoding

AVIF stores AV1-compressed images in the HEIF container family. Microsoft's HEIF codec documentation identifies HEIF support and AV1 decoding as separate requirements for AVIF. Check the requirements of the particular Windows app; installing AV1 alone is not a universal fix.

That decoder stays on this PC. A managed laptop that blocks the Store never receives it at all, and whoever you email the file to is in the same position you were in ten minutes ago.

1. Check the app's AVIF requirements. If it requires the Store codec, use the official AV1 Video Extension; HEIF container support may also be needed.
2. Reopen the viewer after changing its codec setup, then try the original file.
3. Double-click a .avif to confirm it draws in Photos.
4. Still grey, or no Store on this PC? Convert instead.

Animated and HDR AVIF are not the same job

Tinolia accepts still AVIF and rejects animated image inputs. A JPEG output does not preserve AVIF transparency or HDR capabilities. Check the appearance of the converted still, especially highlights and shadows, rather than assuming every viewer will render identical colors.

Make a JPEG for whoever has to open it

The JPEG usually ends up larger than the AVIF, because AV1 reaches the same look in fewer bytes. That extra weight is the price of software that only ever learned JPG and PNG.

1. Drop the .avif. Up to 10 files, 20 MB each.
2. Pick a fill colour if the image had transparency, then download JPEG or a ZIP.
3. If the form also names a cap, run a 200 KB target on the JPEG afterwards.

Transparency needs something behind it

AVIF carries an alpha channel and JPEG does not, so a cut-out logo has to land on some colour. White is right on a white page and obviously wrong the moment the page goes dark.

To keep transparent areas, use AVIF to PNG. Compare the result with the original; converting to PNG does not promise a smaller file.

Check the destination before converting

Keep AVIF when your site and viewers support it. A portal may require JPEG or PNG even when the browser can display AVIF. For an iPhone HEIC that fails to open, see HEIC on Windows.

For an eBay listing or a Workday field, read the destination's accepted types before converting. Browser support on your PC does not establish what that upload permits.