ICO (Icon file) is a ICO format commonly used for favicons, desktop app icons, multi-size icon bundles. This guide covers compatibility, compression, transparency, and conversion choices.
| Feature | Support |
|---|---|
| Transparency | Yes |
| Animation | No |
| Layers | No |
| Primary uses | favicons, desktop app icons, multi-size icon bundles |
Extension
.ico
MIME type
image/vnd.microsoft.icon, image/x-icon
Family
ICO
Compression
container
Browser support
browser favicons and Windows
Stores multiple icon sizes
Recognized for favicons
Supports transparency
Special-purpose format
Not for photos
Editing support varies
ICO is the ImageHQ reference page for Icon file. It explains where the format works well, what tradeoffs to expect, and how to choose between ICO and related formats in production image workflows.
Use ICO when the workflow values favicons, desktop app icons, multi-size icon bundles. This is the practical fit that matters before tuning compression or conversion settings.
- favicons
- desktop app icons
- multi-size icon bundles
The main advantages of ICO are predictable in real projects: stores multiple icon sizes, recognized for favicons, supports transparency.
- Stores multiple icon sizes
- Recognized for favicons
- Supports transparency
ICO is not always the best delivery choice. Watch for special-purpose format, not for photos, editing support varies before using it as a default.
- Special-purpose format
- Not for photos
- Editing support varies
ICO uses container compression behavior. That affects file size, editability, transparency, and whether repeated export cycles can visibly change the image.
Convert ICO files when a recipient, browser, archive, or editing tool needs a different balance of compatibility, transparency, file size, or preservation.
ICO is web-ready when browser support and file size match the use case. Compare it with WebP, AVIF, PNG, and JPG before choosing a default.
ICO transparency support: yes. Use PNG, WebP, AVIF, SVG, or PSD when alpha transparency is required.