How to use it
- Drop in an ICO file, such as a favicon.ico you have downloaded.
- Every size inside is converted to its own PNG.
- Download them as a zip, or just the size you need.
What you will find inside an ICO
Most ICO files hold several versions of the same icon at different sizes. A typical website favicon.ico has 16, 32 and 48 pixel versions; a Windows application icon may go up to 256. Each gets its own PNG, named with its size, so favicon-32x32.png is exactly the 32-pixel artwork from the file.
Older icons store their images as bitmaps with a separate black-and-white mask for transparency. This tool reads those masks and turns them into proper PNG transparency, so you will not get black squares around the edges.
Getting a larger icon than the ICO holds
If the biggest image inside is 32 × 32, that is the most detail available. Enlarging it will just make it blurry or blocky. For a high-resolution version of a site's icon, look for its apple-touch-icon.png (usually 180 × 180) or the icons listed in its web manifest.
ICO and PNG compared
| ICO | PNG | |
|---|---|---|
| First released | 1985 | 1996 |
| Compression | Holds PNG or BMP images | Lossless |
| Transparency | Yes | Yes, including soft edges |
| Animation or pages | Several sizes in one file | Only as APNG, rarely used |
| Best for | Favicons and Windows icons | Screenshots, graphics, text and transparency |
| Support | Browsers and Windows | Universal |
Questions people ask
Why are there several PNG files?
ICO files usually contain the icon at several sizes. You get all of them, largest first.
Can I convert .cur cursor files?
Cursor files use the same structure as ICO, so they usually convert fine.
The icon has a black background. Why?
That is rare with this tool, since it applies the transparency mask. If it happens, the icon was probably drawn with a black background by its designer.