Why an AVIF image needs to become WebP
You saved a picture from a website, and the file ends in .avif. Now the upload form says the format isn't supported. This happens a lot in 2026, because many sites serve AVIF to browsers, but the tools people upload into lag years behind.
WebP is the safer modern format. Google released it in 2010, and Shopify, Squarespace, WordPress and Microsoft 365 all accept it. AVIF only reached version 1.0 in February 2019, and AVIF uploads are still refused by Shopify and Squarespace today. If a form takes WebP but rejects AVIF, converting is the fix. Renaming the file is not: the bytes inside are still AV1 data, and the upload will fail again or show a broken image.
How to convert AVIF to WebP
- Drop your .avif file into the box above, or tap it to pick one. You can add up to 5 files at once, each up to 300 MB.
- WebP is already set as the target. Press Convert. The file is uploaded to our server, where the AVIF is decoded and re-encoded as WebP.
- Download the .webp file and upload it wherever the AVIF was refused.
No account is needed, there's no watermark, and it's free.
Which platforms accept WebP but refuse AVIF
Each row comes from the platform's own help pages or release notes.
| Platform | WebP upload | AVIF upload |
|---|---|---|
| WordPress | Yes, since 5.8 (July 2021) | Since 6.5 (April 2024), and only if the host's PHP image library (GD or Imagick) was built with AVIF support. Check Tools, Site Health. |
| Shopify | Yes | No. Accepted uploads are JPEG, PNG, GIF, HEIC and WebP. Shopify makes its own AVIF copies when serving. |
| Squarespace | Yes (.webp is on the accepted list) | No. Accepted types are .jpg, .gif, .png and .webp, up to 20 MB. |
| Wix | Yes | Yes |
WordPress is the most common case. A site still on 6.4 or below rejects .avif at the media library. On 6.5 and later the upload can go through while thumbnails quietly fail to generate, because the host's image library can't read AVIF. WebP avoids both problems.
Desktop software is patchy too. Windows Photos only opens AVIF after you install the free AV1 Video Extension from the Microsoft Store. Photoshop opens and saves AVIF from version 26.8 (June 2025). Microsoft 365 apps have taken WebP through Insert Picture since late 2021.
What actually changes inside the file
AVIF stores an image compressed with AV1, a video codec (compression method), inside a HEIF container, the file wrapper Apple also uses for HEIC. WebP stores a VP8-compressed image inside a RIFF wrapper. Converting means fully decoding the AVIF to pixels and compressing those pixels again as WebP.
Three things follow from that.
- The WebP is usually larger than the AVIF. AV1 compresses more tightly than VP8 at the same visual quality, so expect the file to grow. It will usually still be much smaller than a PNG of the same picture.
- Quality drops slightly, twice over. The AVIF already threw away detail when it was made. Lossy WebP throws away a little more. On a normal photo at normal size you won't notice. On a heavily compressed AVIF you may see slightly softer edges.
- Colour depth is capped at 8 bits. AVIF can hold 10-bit and 12-bit colour and HDR (extra bright, high-contrast images). Lossy WebP stores 8-bit colour only. An HDR AVIF comes out as a standard-range WebP, and smooth gradients can show faint banding.
Transparency survives. Both formats can store it, so a product cut-out on a clear background stays a cut-out. Animated AVIF does not survive: only the first frame is converted. WebP also can't be wider or taller than 16,383 pixels, so a giant AVIF (a stitched panorama, for example) should go to PNG or TIFF instead.
When JPG or PNG is the better target
Pick WebP when the destination lists WebP. Pick something older when it doesn't, or when you're not sure.
- A print shop, a government portal or an old desktop program usually wants JPG. Use AVIF to JPG. You lose transparency, but nothing else of note.
- A logo or screenshot that will be edited again should go to AVIF to PNG. PNG doesn't apply a second lossy compression, so no further detail is lost each time the file is saved.
- A photo going into a report can go straight to AVIF to PDF.
All the targets we support are listed on the AVIF converter page, and everything that can be made from or into WebP is on the WebP converter page.
Building a website? Keep the AVIF and add WebP as the fallback
If the AVIF is your own image and the problem is that some visitors can't see it, don't replace it. Serve both. Safari only started showing AVIF with iOS 16 (September 2022) and Safari 16.4 on Mac, and Edge with version 121 (January 2024), while WebP has worked in Safari since version 14 (2020), Firefox since 65 and Edge since 18. The HTML picture element lets the browser pick the first format it understands:
<picture>
<source srcset='photo.avif' type='image/avif'>
<source srcset='photo.webp' type='image/webp'>
<img src='photo.jpg' alt='Describe the photo' width='1200' height='800'>
</picture>Converting your AVIF here gives you the second line. For the third line, convert the same file with AVIF to JPG, or keep the original JPG if you still have it. Google has indexed AVIF in Image Search since August 2024, so there's no SEO reason to drop the AVIF version.
If the WebP still won't upload
Check the size first. Squarespace caps images at 20 MB, and most forms have a limit somewhere. If the WebP is over it, shrink the pixel dimensions with our image resizer and convert again. A 6000-pixel-wide photo is rarely needed on a web page.
Then check the file name. It should end in .webp, not .avif.webp from a rename on top of a rename. Windows hides known extensions by default, which is how that happens.