Files with G64 extension are used for storing disk images. G64 files were used by Commodore 64 computer, a piece of hardware popular during the 1980s and 1990s. G64 files typically store data from 5,25 diskettes or external HDD.

G64 files were also used for storing Commodore 64 games or programs written for this machine. There are some emulators available for Windows and MacOS that can run G64 files on more modern platforms.