ICO (Microsoft icon file)

The ICO Raster image file format

Files with the ICO extension are commonly used by the Microsoft Windows operating system in order to display a picture that is used for a computer icon. It can be used for item icons in the start menu, shortcuts, directories, or for programs. In order for the computer to associate a picture with a certain file or program, it is mandatory to use a file with the ICO file extension. The ones most commonly known are, among others, the small computer icon on your icon used to direct you to the "My Computer" directory, or some kind of sheet or notepad which is commonly associated with different word processing programs like Microsoft Word, OpenOffice Writer, or Notepad.

Technical details of ICO files

ICO files have been part of the earliest versions of Microsoft Windows already. Over the time, the file format has evolved and improved when it comes to color support or maximum size of pixels allowed. Currently, in the Windows 7 standard, the icons can be up to 256 x 256 pixel in size and incorporate 8 bit transparency and 24 bit color.

More information about the ICO file format

File extension .ico
File category Raster image
Example file Download example.ico file (238.17 KiB)
Download example_small.ico file (373.01 KiB)
Associated programs Adobe Photoshop
Microsoft Paint
Windows Picture and Fax Viewer
Useful links Read more about the ICO file
File conversion Convert a file to ICO
Developer Microsoft