Convert AVIF to ICO (favicon)
Probably the newest-to-oldest conversion on this site: AVIF is barely five years old, ICO shipped with Windows 3.0. The pipeline is simple — your AVIF decodes in the browser, gets center-cropped square, and comes out as one .ico holding 16, 32 and 48px icons with the alpha channel intact.
Need the other direction? Convert ICO to AVIF
How it works
Add the AVIF logo or mark; your browser decodes it locally with the alpha channel intact.
The tool squares it up and writes the standard 16, 32 and 48px entries into one Windows-native container.
Expect the .ico to outweigh the tiny AVIF — icons store raw pixels — then download it solo or in the batch zip.
AVIF vs ICO
Thirty-three years separate these formats, and the pipeline could not care less: the AVIF decodes to exact pixels, the ICO stores them uncompressed at icon sizes. The verdict is pragmatic — the best favicon source is whichever clean copy of your mark you actually possess.
| AVIF | ICO | |
|---|---|---|
| Compression | Lossy or lossless | Lossless (BMP or PNG entries) |
| Transparency | Yes (full alpha) | Yes (full alpha) |
| Animation | Yes (rarely used) | No |
| Support | All current browsers (Safari since 16.4, 2023) | Universal for favicons |
| Best for | Hero images and photo-heavy pages | Favicons and Windows app icons |
Frequently asked questions
No — that is the whole reason I built this. The conversion runs in your browser using WebAssembly, so your files never leave your device; there is no server in the loop at all. It also means the tool keeps working offline once the page has loaded, and there is no file size limit beyond your device’s memory.
Browsers render AVIF in pages, but favicon handling is more conservative — and plenty of non-browser consumers (crawlers, feed readers, bookmark managers) only ever fetch /favicon.ico. The .ico is the one format every one of them understands, which is why it refuses to die.
The AVIF decodes exactly, and the icon entries are stored uncompressed with full alpha — so nothing is lost beyond the downscaling to icon sizes, which is inherent to making a favicon. At 16px, honestly, codec fidelity is the least of your worries; a strong simple shape is what matters.
Anything square and 48px or larger. Bigger sources downscale fine — a 512px logo works great. What hurts is going the other way: a 32px source has to be upscaled to fill the 48px entry, and that always looks soft.
Neither, really — after decoding, both hand the encoder the same pixels, and the .ico stores them uncompressed. The difference is upstream: AVIF logos saved off the web sometimes carry subtle compression smoothing that shows at 16px. If you have both exports, pick the PNG; if the AVIF is what you have, this converts it without any further loss.
Trying to preserve AVIF’s efficiency — the .ico format stores raw 32-bit bitmaps, so a 20 KB AVIF becomes a ~100 KB icon file regardless of source. That is normal and fine for a favicon fetched once and cached. If what you actually want is a small web-ready image rather than a favicon, AVIF to WebP is the tool you meant to open.
Related tools
Convert WebP to ICO (favicon)
Convert WebP to ICO in your browser — free, private, no upload. Turn a logo saved as WebP into a proper multi-size favicon, transparency carried through.
Convert PNG to ICO (favicon)
Convert PNG to a multi-size ICO favicon in your browser — free, no upload. One file with 16, 32 and 48px icons with full alpha, ready for any site root.
Convert AVIF to PNG
Convert AVIF to PNG in your browser — free, lossless output, transparency preserved, no upload. Open AVIF files saved from the web in any editor, viewer or app.
Convert ICO to AVIF
Convert ICO to AVIF in your browser — free, private, no upload. Extract a favicon into the smallest modern image format, alpha channel kept fully intact.