The file format consists of an 8 byte header, followed by any number of icons.
The fixed-size icons can be scaled by the operating system and displayed at any intermediate size.Īs of macOS 11, asset catalogs are the preferred file format for macOS custom icons instead. It supports icons of 16 × 16, 32 × 32, 48 × 48, 128 × 128, 256 × 256, 512 × 512 points at 1x and 2x scale, with both 1- and 8-bit alpha channels and multiple image states (example: open and closed folders). The Apple Icon Image format (.icns) is an icon format used in Apple Inc.'s macOS.
