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Why convert OTB to ICO?
Fast
Your file is converted in under 30 seconds in our cloud.
Secure
Files are automatically deleted after 1 hour.
Quality preserved
Maximum quality preserved during conversion.
About the OTB format
OTB — On-the-air Bitmap (Nokia)
OTB is a monochrome bitmap format originally used by Nokia feature phones for sending and receiving images over SMS (picture messages). It was a standard format in early mobile phones of the late 1990s and 2000s for simple graphics like logos and ringtone icons.
Common uses
- Nokia mobile phone picture message images
- Converting legacy feature phone graphics
- Historical mobile messaging image recovery
- Early mobile logo and icon conversion
About the ICO format
ICO — Windows Icon
ICO is the standard icon format for Windows, storing one or more images at different resolutions within a single file. Modern ICO files can contain high-resolution PNG-compressed images alongside traditional BMP frames for compatibility across all Windows versions.
Common uses
- Windows application and file type icons
- Website favicon (favicon.ico)
- Windows shortcut and executable icons
- Cross-resolution icon sets for Windows UI
Related conversions
Other conversions available for OTB and ICO files
Frequently asked questions
Is the conversion free?
Yes, basic conversion is completely free. For large volumes, check out our paid plans.
What is the maximum file size?
Free accounts can convert files up to 25 MB. Pro accounts up to 100 MB.
How long are my files kept?
Files are automatically deleted after 1 hour on the free plan, 24 hours on Pro.
What formats are supported?
We support over 200 source and target formats. See our complete formats page.