ICO
A Microsoft Windows icon format that can store multiple icon sizes and color depths inside a single file.
General information
- Format name
- Windows Icon
- Extension
.ico- MIME type
image/vnd.microsoft.icon- Category
- image
- Data type
- Binary
- Developer
- Microsoft
Image properties
- Structure
- Raster
- Compression
- Varies
- Transparency
- Yes
- Animation
- No
File signatures
| Offset | Hexadecimal | ASCII | Description |
|---|---|---|---|
| 0 | 00 00 01 00 | — | Standard ICO header identifying an icon resource. |
Common uses
Website favicons
Windows application icons
Desktop shortcuts
Software interface icons
Related formats
Technical resources
| Resource | Publisher | Link |
|---|---|---|
| Image file type and format guide | MDN Web Docs | Open resource ↗ |
| Media Types Registry | IANA | Open resource ↗ |
Record information
- Verified
- October 3, 2026
- Last updated
- October 3, 2026