How to convert AVIF to ICO online
- 1
Drop your AVIF file
Drag your AV1 Image File Format file onto the box above, or click it to pick a file.
- 2
Wait a few seconds
Conversion starts on its own and runs on your device, not on a server.
- 3
Download your ICO
Click Download to save the Windows Icon Format file.
AVIF vs ICO: format overview
AV1 Image File Format
Alliance for Open Media · 2019
- Compression
- lossy
- Color depth
- 12-bit
- Transparency
- Yes
- ✓ Smallest file size of any image format (50% smaller than WebP)
- ✓ Excellent HDR and wide-gamut color support
- ✗ Slow encoding (computationally expensive)
Windows Icon Format
Microsoft · 1985
- Compression
- lossless
- Transparency
- Yes
- ✓ Multiple resolutions in a single file
- ✓ Required format for Windows app icons and favicons
AVIF magic bytes: 00 00 00 .. 66 74 79 70 61 76 69 66
ICO magic bytes: 00 00 01 00
Why convert AVIF to ICO?
AVIF is increasingly common as a web image format, and it's natural to want to use an existing AVIF graphic — a logo, an icon, a brand mark — as a favicon or Windows application icon. The problem is that browser favicon pipelines and Windows icon tooling don't accept AVIF files directly; they need ICO.
ICO is the container format for Windows icons and browser favicons. It packages one or more image sizes — 16×16, 32×32, 48×48, and sometimes 256×256 — into a single file. When you convert AVIF to ICO, the tool handles both the format conversion and the resizing needed for the different icon sizes. Browsers automatically pick the right size for the context (browser tab, bookmark, home screen shortcut).
For best results, the source AVIF should be a square graphic with a clear subject centered in the frame. Complex scenes and photographs rarely look good at 16×16 or 32×32 pixels — the detail simply disappears. If the AVIF contains a logo or icon-style graphic, the conversion will work well. After converting, test the favicon using a tool like RealFaviconGenerator to check how it renders across browsers and operating systems before publishing it.
Quality & file size: AVIF to ICO
Typical sizes: AVIF 0.8–2 MB (12MP photo); ICO 10–100 KB (multi-size icon).
ICO will not bring back detail that AVIF compression already removed, but it adds no further loss — handy when you need to edit the image.
Frequently asked questions
What ICO sizes does the converter produce?
Should I convert a high-resolution AVIF to ICO?
Your AVIF file never leaves this tab — FormatDrop has no endpoint that receives file data. How it works