I would like to know the range of icon sizes allowed in different OSes (such as Ubuntu, OSX) and the default format they use.

For example, windows allows icon sizes from 16x16 to 256x256 and uses a .ico file.

2 Answers 2


First of all, both Windows and Mac OS X encapsulates their icons in a container format, meaning that instead of multiple images with different sizes, the file carries images of different resolutions, and the operating system decides on when to use which.

Windows uses the .ico format. Pre-Vista, the icons should range from 16x16 to at most 48x48 big and are stored internally as bitmap files. With Vista, sizes up to 256x256 are allowed, and the underlying file format is changed to png.

Mac OS X uses .icns files, with sizes from 16x16 up to 512x512. It can also carry multiple states in the same file.

Linux is distro dependent, but generally supports a wide range of formats. For compatibility though, you would want to use multiple PNG files for the different resolutions, or a single vector SVG file. Resolutions also differs, but generally speaking 16x16 up to 512x512 should suffice.

  • 2
    Linux distros use lots of pngs. Icon themes come with folder of varying sizes (from 16-512, but usually they max out at 48 or 64) and a scalable folder. The icons have the same name in each folder size, and the system knows how to translate to the next size when needed.
    – dkuntz2
    Jan 12, 2011 at 14:31

Mac OS X use the .icns icon file extension, and supports 16x16 up to 512x512 resolution.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.