Image
What is a .ico file?
A .ico file is an Icon file format. This is an image format — a picture, drawing or graphic. Confusingly, this extension has been used by 3 different formats over the years — they're all listed below.
This extension has been used by more than one format
3 different formats have claimed .ico over the years, so two files with the same extension aren't necessarily the same kind of thing.
How to open a .ico file
- GIMP (free) and IrfanView open a very wide range of image formats, including obsolete ones.
- XnView MP is the best bet for unusual or legacy image types.
- Your operating system's built-in viewer may work for mainstream formats.
The registry records this extension against Icon file format, Alias Pix Image File, Maya IFF Image File, so software from that family is the most likely match.
How to convert a .ico file
- Open it in GIMP or XnView and export as .png (lossless) or .jpg (smaller).
MIME type
When a .ico file travels over the web, servers label it with one of these MIME types:
image/vnd.microsoft.iconimage/x-iconThe technical record
For archivists, developers and the merely curious: these are the PRONOM registry entries for .ico.
| Format name | Version | MIME type | PUID |
|---|---|---|---|
| Icon file format | — | image/vnd.microsoft.icon, image/x-icon | x-fmt/418 |
| Alias Pix Image File | — | — | fmt/1092 |
| Maya IFF Image File | — | — | fmt/1169 |