ICO (Windows icon)

ICO is the icon file format used by Microsoft Windows for programs, shortcuts and folders. A single ICO file can contain the same image at several sizes and colour depths, such as 16×16, 32×32 and 256×256 pixels, so the system picks the best one for each context. It supports transparency, and modern ICO files can embed PNG images inside.

Use ICO for Windows application icons and for favicon.ico, the small icon browsers show in tabs and bookmarks. Include several sizes so the icon stays sharp everywhere. For other purposes, a PNG or SVG is easier to work with.

Source formats: .ico