Z64 files are used to store backups of the contents of cartridges used in older Nintendo 64 game consoles. Such files were often stored on ZIP disks. A tool called Mr. Backup Z64.

Nintendo 64 ROM images, in addition to serving as backups, can be used to run games on computers running Windows or Mac OS. However, this requires the installation of an application that is an emulator of the Nintendo 64 console on the system.