AVIF to ICO Converter

What Is the AVIF to ICO Converter?

This tool converts an AVIF image to Windows Icon entirely in your browser -- the file is decoded, redrawn onto a canvas, and re-encoded as ICO without ever being uploaded to a server. AVIF (AV1 Image File Format) is a modern, highly compressed image format; ICO is the format Windows and browsers expect for favicons and app icons, so this bridges a format almost nothing accepts as a favicon into one every platform does.

How to Use This Tool

Click the upload area and choose an AVIF file. The converted preview appears immediately; click Download to save it as a real .ico file.

Why Convert AVIF to ICO

The most common reason to convert AVIF to ICO is building a favicon or a Windows app icon -- most platforms that ask for a favicon file specifically want a real .ico, not a renamed PNG/JPG. This tool embeds your image as a single PNG-in-ICO entry (the same approach browsers themselves accept for a site favicon) rather than the old multi-resolution ICO bundles image editors sometimes produce. The image is never resized: it keeps its original pixel dimensions, and the ICO directory size fields are written as 0, which the ICO format treats as 256, so resize your source first if you need a specific icon size.

What the Tool Actually Produces

Your browser decodes the AVIF, the tool draws it onto a canvas at the image's own pixel dimensions, and the canvas is saved as a PNG. That PNG is then wrapped in a minimal ICO container with a single image entry. Images larger than 256 pixels on a side are scaled down to fit the ICO limit, and no additional icon sizes are generated. If you upload a 512 by 512 AVIF, the icon inside the file holds 512 by 512 pixels of PNG data. Transparency is kept, since PNG supports it and no background is filled in.

One technical detail worth knowing: the ICO directory entry records the real width and height of the image (a size of 256 is stored as zero, as the icon specification defines). Older Windows software that relies on the directory entry therefore sees the correct size. A square source close to 256 by 256 pixels gives the sharpest result.

Preparing a Good Source Image

• Make it square. A non-square source is stored as-is and can look stretched or padded wherever the icon is shown. Crop first if needed.
• Choose a simple design. Favicons are displayed very small, often at 16 or 32 pixels in a tab. Detailed photos turn into mush; bold shapes and high contrast survive.
• Pick a sensible size. Around 256 by 256 pixels is a practical target for this tool. A very large source produces an unnecessarily heavy icon file, and there is no size limit built in.
• Use transparency deliberately. A transparent background works well on both light and dark browser themes, but make sure your artwork is still readable on both.

A Worked Example

Say you designed a logo mark as a 256 by 256 AVIF and your web host's favicon field only accepts .ico. Upload the AVIF, check that the preview and the reported 256 by 256 dimensions look right, and download logo.ico. The size badge may show a small AVIF growing considerably, for example from 6 KB to 30 KB. These numbers are only illustrative; PNG data is usually bigger than AVIF for the same picture, and that is fine for an icon of this scale.

Limits and Things to Check

• Single size only. Traditional icon tools bundle 16, 32, 48 and larger versions in one file. This tool does not, so scaling down to tab size is left to the browser or operating system.
• Browser must read AVIF. If your browser cannot decode the file, you will see an error instead of a preview.
• Animated AVIF gives one frame. Icons are static, so only a single frame is captured.
• Test it where it counts. After uploading the icon to your site, hard refresh or clear the cache, since browsers cache favicons aggressively and may keep showing the old one for a while.
• Modern alternatives exist. Many sites also supply a PNG or SVG favicon through link tags. An ICO file is still worth having for legacy tools, Windows shortcuts, and platforms that request it by name.

Related Uses

Beyond websites, a .ico file is what Windows expects for desktop shortcut icons and some application installers. If the shortcut looks blurry in a large view, the source was probably too small; start again from a bigger, sharper image instead of converting an already-tiny one.

Frequently Asked Questions