N64 ROM formats

File extensions

Extension Usual byte order Notes
.n64 Byte-swapped Previously used by No-Intro
.n64 Little-endian Very rare
.v64 Byte-swapped Named after the Doctor V64 backup device
.z64 Native Named after the Z64 backup device

Note that the actual byte order of a ROM may not always be the one expected from its file extension.

Byte orders

Format Order Header (hex) Example string
Native ABCD 80 37 12 40 SUPER␣MARIO␣64␣␣
Byte-swapped BADC 37 80 40 12 USEP␣RAMIR␣O46␣␣
Little-endian (rare) DCBA 40 12 37 80 EPUSAM␣R␣OIR␣␣46