Convert AVIF to ICO
Output is typically about 93% smaller.
- Files stay on your device
- Free, no sign-up
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Will converting AVIF to ICO make the file smaller?
Usually, yes. A 12-megapixel photo is around 1.4 MB as AVIF and around 100 KB as ICO — about 93% smaller. Because ICO is lossless the result depends entirely on the image content — flat colour and text compress far better than photographic detail.
Does converting AVIF to ICO lose quality?
No. ICO is lossless, so every pixel decoded from your AVIF file is stored exactly. Both formats are lossless, so the conversion is pixel-for-pixel identical.
Is transparency preserved when converting AVIF to ICO?
Yes. Both AVIF and ICO support an alpha channel, so transparent and semi-transparent pixels carry across unchanged — a logo with a cut-out background stays cut out, and soft drop shadows keep their gradient rather than picking up a white halo. Because ICO is lossless, the alpha channel is stored exactly as it was.
What happens to an animated AVIF?
Only the first frame is converted. Every conversion here decodes one frame onto a canvas and re-encodes it, so the result is always a still image — that applies to ICO as much as to any other target. To shrink an animation while keeping the motion, a video file (MP4 or WebM) is usually around a tenth of the size of the equivalent AVIF, and needs an encoder we do not ship yet.
What size should a favicon be?
Start from a square source image of at least 256 × 256 pixels. An ICO bundles several resolutions in one file — 16, 32, 48 and 256 pixels covers browser tabs, bookmarks and Windows shortcuts. Modern sites usually pair favicon.ico with a 180 × 180 PNG for Apple touch icons and an SVG for scalable tab icons.
What sizes are in the ICO file?
Four — 16, 32, 48 and 256 pixels — packed into a single file, each stored as PNG. That is the point of the format: the browser or operating system picks whichever size it needs, so one favicon.ico covers tab icons, bookmarks and Windows shortcuts. Non-square images are centred rather than stretched, so start from a square source if you can.
How it works, and more about avif to ico
How it works
- Add your AVIF file. Drag a AVIF file onto the drop zone, or click to browse. You can select several at once.
- Choose your settings. ICO is lossless, so there is nothing to configure — the output matches the input pixel for pixel.
- Download the ICO. Conversion runs on your device as soon as each file is added — no upload, no queue. Download each result when it is ready.
AVIF and ICO side by side
| AVIF | ICO | |
|---|---|---|
| Full name | AV1 Image File Format | Windows Icon |
| Compression | Lossy or lossless | Lossless |
| Transparency | Yes — alpha channel | Yes — alpha channel |
| Animation | Yes | No |
| Browser support | Chrome 85+, Firefox 93+, Safari 16.4+ (March 2023), Edge 121+ | Universal for favicons |
| Typical 12 MP photo | ~1.4 MB | ~100 KB |
| Usually used for | Performance-critical web images where every kilobyte counts | Website favicons and Windows application icons |
On a typical 12-megapixel phone photo, the ICO output comes out about 93% smaller than the AVIF original. These are order-of-magnitude figures for one kind of image — your own results will vary a great deal, because flat colour, text and line art behave nothing like photographic detail.
What this tool actually produces
Not estimates. Each row below was produced by running the file through this page in a real browser and measuring the result, at the default quality of 82.
| Test image | AVIF in | ICO out | Change |
|---|---|---|---|
| Smooth gradient 1600 × 1200, broad tonal transitions — where banding and blocking show | 53 KB | 84 KB | +60% |
| UI screenshot 1440 × 900, dense text on flat panels — the hardest case for JPEG | 22 KB | 23 KB | +5% |
| Logo with transparency 512 × 512, flat colour on a transparent background | 3 KB | 35 KB | +993% |
Every test image got larger. That is expected for this pair rather than a fault: ICO is not the efficient choice for content that already suits AVIF, and you are converting for compatibility or for editing headroom, not to save space. Measured in Chrome 150.0.7871.46; other browsers encode slightly differently.
What to watch out for
- Only practical at small icon sizes
- Obsolete for general imagery
- Modern sites increasingly prefer SVG or PNG favicons
- Animation is lost. Only the first frame is converted — every conversion here decodes a single frame onto a canvas and re-encodes it, so the result is a still image whatever the target format. To shrink an animation and keep the motion, a video file is typically around a tenth of the size of the equivalent AVIF.
About the two formats
AVIF currently produces the smallest files of any widely supported format — commonly half the size of JPEG at the same perceived quality, with excellent handling of gradients and noise. The cost is encoding time, which can be seconds per image rather than milliseconds, and support that only became universal with Safari 16.4 in 2023.
ICO is a container rather than a codec: it bundles the same icon at several sizes — typically 16, 32, 48 and 256 pixels — so the operating system or browser can pick the right one. Its remaining job is the favicon at the root of a website, and Windows application icons.
Other conversions
Everything runs on your device — nothing is uploaded, so there is no size limit, no queue and no copy left on a server afterwards. There is more on how browser-based conversion works if you want the detail. Otherwise, browse every image tool, or convert ICO back to AVIF.