Game Genie Code Decoder
Decode Game Genie cheat codes to see the exact memory address, original value, and replacement value.
How Game Genie Works
Game Genie codes work by intercepting the console's memory bus. When the CPU reads a specific memory address, Game Genie substitutes a different byte value — making the game behave differently without modifying the ROM itself.
NES codes use a custom alphabet APZLGITYEOXUKSVN where each letter maps to a 4-bit hex digit (0–15). A 6-letter code encodes an address and replacement value. An 8-letter code also encodes a compare value — the substitution only happens when the original byte matches, preventing the code from firing at the wrong time (e.g. when the same address stores different data during cutscenes).
SNES codes are similar but operate in a 24-bit address space. Game Boy codes target the Game Boy's 16-bit address map (0x0000–0xFFFF). Sega Genesis codes work on the 68000 CPU's address bus.
Decoding reverses the bit-scrambling to recover: the address (which memory location to intercept), the replacement value (the byte to inject), and optionally the compare value (the original byte that must be present).