Canonical: https://rom-weaver.com/apply-cheats

# Apply cheat codes to ROMs online | rom-weaver

Apply supported cheat codes to ROM files locally in your browser and download the modified ROM. No uploads or account required.

[Open in browser](https://rom-weaver.com/apply-cheats)

[Documentation](https://rom-weaver.com/docs.md)

[Full guide](https://rom-weaver.com/docs/use-cheats.md)

## Add cheats to a ROM

The [guided Apply cheats tour](<https://rom-weaver.com/apply-rom-patches?guide=apply-cheats>) uses a supplied homebrew ROM and a working practice code.

The picker includes **Make the greeting start with M** (`80970D`) and **Change the background color** (`8077300F`). These are practice codes for the supplied homebrew ROM only.



1. Open [Apply cheat codes](<https://rom-weaver.com/apply-cheats>) and add the original ROM.
2. In **Patches & Cheats**, select **Add cheats to the patch order**.
3. Choose the system and game if the dialog asks.
4. Search the list and add the cheats you want.
5. Close the dialog and check the selected cheats in the patch order.
6. Move each cheat before or after the patches that it must use.
7. Choose **APPLY & DOWNLOAD** and save the output ROM.

Check the game and revision yourself when the database only matches a title. A title match is not an exact ROM match.

Unsupported codes show a reason and cannot be selected. Resolve reported write conflicts before Apply; do not assume the last code wins.

Use each card's inclusion control to leave a step out without removing it. Patch and cheat order both affect the result.



## Add a code manually

1. Open **Add cheats to the patch order**, then **Add code manually**.
2. Enter the code and an optional description.
3. Keep automatic system and code-type detection, or select an override.
4. Select **Check code**, then read the detected system, code type, and delivery result.
5. Add the code when the result matches your game.

Select Pro Action Rocky explicitly for an eight-digit NES code. For a GBA code, select the exact GameShark or Action Replay version. Select a `raw` version only for an already decrypted block. Keep all lines of a versioned GBA block together.

Codes with unresolved `?` or `X` placeholders cannot be added. Gold Finger `XX` trailing data slots are valid unused bytes. Codes that need live game memory cannot become ROM changes.