How to use it
- Choose the sizes to include. 16, 32 and 48 cover favicons; add 256 for Windows desktop icons.
- Drop in your image. Non-square images are centred on a transparent square.
- Download the .ico file.
Why an ICO file holds more than one image
An ICO is a small container. Windows and browsers look inside and pick the size closest to what they need. A 16-pixel tab icon scaled down from a 256-pixel image can look muddy, so good icon files include the small sizes directly. This converter draws each size separately from your original, with careful downscaling, and stores them all as PNG data inside the ICO. Every version of Windows since Vista and every current browser reads this kind of ICO.
Which sizes to tick
| Size | Where it is used |
|---|---|
| 16 × 16 | Browser tabs, bookmarks, small list views |
| 24 × 24 | Some Windows toolbars |
| 32 × 32 | High-density browser tabs, taskbar |
| 48 × 48 | Windows desktop at normal scale, site shortcuts |
| 256 × 256 | Large icons in File Explorer, Windows app icons |
For a website, the full set of favicon files goes beyond the ICO. The favicon generator makes the Apple and Android sizes as well and gives you the HTML to paste in.
Design tip for tiny sizes
Detail disappears at 16 pixels. A bold initial or simple shape reads better than a detailed logo. If your logo has a wordmark, consider using just the symbol for the icon.
PNG and ICO compared
| PNG | ICO | |
|---|---|---|
| First released | 1996 | 1985 |
| Compression | Lossless | Holds PNG or BMP images |
| Transparency | Yes, including soft edges | Yes |
| Animation or pages | Only as APNG, rarely used | Several sizes in one file |
| Best for | Screenshots, graphics, text and transparency | Favicons and Windows icons |
| Support | Universal | Browsers and Windows |
Questions people ask
Can I convert a JPG to ICO?
Yes. Any image your browser can open works. JPGs have no transparency, so the icon will have a solid background.
What size should the original image be?
At least as big as the largest size you tick. 512 × 512 or an SVG gives the best results.
Does the ICO support transparency?
Yes. Each size is stored as PNG data with a full alpha channel.