ICO is the Windows icon container format. A single .ico file can hold several image sizes so the operating system or browser can pick the sharpest one for each context, such as a 16px tab favicon or a 48px desktop shortcut.

Which sizes should I include?

For a website favicon, 16, 32 and 48px covers almost everything. Add 64, 128 or 256px if you also want a crisp desktop or taskbar icon.

What sizes can the tool embed?

You can choose any of 16, 32, 48, 64, 128 and 256 pixels. The selected sizes are each rendered from your PNG and bundled into one multi-resolution .ico file.

Should my source PNG be large and square?

Yes. Start from a square PNG at least 256×256 so every embedded size is downscaled from a sharp original. Downscaling looks clean; upscaling a small PNG to 256px would look blurry.

Does the ICO keep transparency?

Yes. The converter draws each size from your PNG including its alpha channel, so transparent backgrounds stay transparent in the icon.

Where do I put the .ico for a website?

Place it at your site root as favicon.ico, or reference it with a tag. Browsers automatically pick the best embedded size from the single file.

Are my images uploaded anywhere?

No. The conversion runs entirely in your browser using the canvas API, so your PNG never leaves your device.

PNG to ICO Converter

PNG to ICO — make a Windows favicon in your browser

Convert a PNG into a Windows .ico icon with multiple sizes baked into one file. The converter draws your image at each size you pick and bundles them into a single multi-resolution .ico, so browsers and Windows always have a sharp icon to show — whether it is a 16px tab favicon or a 256px desktop shortcut.

How it works

An ICO file is a small container: a header, one entry per embedded image, then the image payloads. The tool renders your PNG at each chosen size and assembles them:

for each selected size (16, 32, 48, 64, 128, 256):
  draw the PNG onto a <canvas> at that size (alpha preserved)
bundle all sizes into one .ico container (ICONDIR + entries + payloads)

Because several sizes live in one file, the OS or browser always has a resolution that fits the slot it needs to fill.

Example

Starting from a 256×256 logo PNG and ticking 16, 32 and 48px produces a single favicon.ico containing all three sizes — about right for a website. Add 256px as well if you want a crisp Windows desktop icon from the same file.

Use case	Sizes to include
Website favicon	16, 32, 48
Desktop / taskbar icon	+ 64, 128, 256

Everything runs locally in your browser. Your images are never uploaded.