UlvixorImage to ICO Converter (Favicon)
Upload an image and turn it into a multi-resolution .ico file ready to use as a website favicon or desktop app icon. Choose which sizes to include, and everything is generated locally in your browser with canvas — the file is never uploaded to a server.
How it works
- Select an image from your device using the file picker (ideally square and with good resolution).
- Check the sizes you want to include in the .ico: 16×16, 32×32, 48×48, 64×64, 128×128, and/or 256×256 pixels.
- For each selected size, the image is redrawn onto a <canvas> of that size and encoded as PNG.
- The resulting PNGs are packaged into a hand-built ICO container (an ICONDIR header plus one ICONDIRENTRY per size) — the same format favicon generators use.
- Download the final favicon.ico file, ready to upload to your website's root.
Use cases
- Generate a website's favicon.ico from a PNG or JPEG logo.
- Create a multi-resolution icon for a Windows desktop application.
- Convert a square logo into an .ico compatible with browsers and older systems that still expect that format.
- Produce several icon sizes in a single file without using desktop software.
Use cases
- Generate a website's favicon.ico from a PNG or JPEG logo.
- Create a multi-resolution icon for a Windows desktop application.
- Convert a square logo into an .ico compatible with browsers and older systems that still expect that format.
- Produce several icon sizes in a single file without using desktop software.
Common mistakes
- Uploading a rectangular image expecting the resulting icon not to look distorted.The image is stretched to fill each square size selected. Crop the image to a 1:1 ratio before converting to avoid distortion.
- Thinking you need to generate a separate .ico file for each size.A single favicon.ico file can hold several resolutions at once; check every size you need and the tool packages them together into one file.
- Using a low-resolution image and expecting good quality at the large sizes (128×128, 256×256).Each size is generated by resizing the original image, so if the source is small or low quality, the larger sizes will come out blurry or pixelated. Start from an image of at least 256×256 pixels if you'll include the largest sizes.
Frequently asked questions
No. All the resizing and packaging of the .ico file happens in your browser via canvas and JavaScript. The image is never sent to any server.
For most websites, 16×16, 32×32, and 48×48 are enough (these are this tool's default sizes). If the icon will also be used as a desktop app shortcut or on high-density screens, it's worth adding 64×64, 128×128, or 256×256.
Any format your browser can display natively: PNG, JPEG, WebP, GIF, BMP, or SVG. For best results, use a square image, since it's resized directly to each chosen size without cropping.
Since Windows Vista, the ICO format supports PNG-compressed entries, which is exactly what this tool generates. It's compatible with all modern browsers and Windows versions, and produces lighter files than classic uncompressed bitmaps.
Yes, but the result will look distorted because the image is stretched to fill each square size. For best results, crop the image to a 1:1 ratio before converting.
Alternatives
Sites like favicon.io or editing software like GIMP with the ICO plugin also generate this format. This tool is convenient because it generates the full multi-resolution .ico in a single step, right in your browser, with no plugin to install and no logo uploaded to a server.