PatchMyROM

NES ROM Patcher

NES ROM hacking is where IPS came from in the first place. This tool applies those patches the same way it handles everything newer — locally, in your browser.

IPS

The Format That Started It All

Long before Game Boy Advance or Nintendo DS hacking existed, NES and SNES translation groups needed a way to share their work without redistributing copyrighted ROMs. IPS was the answer, and NES hacking has stayed close to it ever since. Most NES ROMs are small enough that IPS's size ceiling never becomes a practical issue, so there's rarely a reason for a project to move to anything newer.

Step-by-Step

1

Get a clean .nes ROM

An unmodified dump of the original cartridge, without any header oddities from an unusual dumping tool.

2

Download the .ips patch

NES hacking has used IPS since long before most other formats existed, so this is what you'll almost always find.

3

Load both into the patcher

The format is detected from the patch file itself — no configuration needed.

4

Download and play

The result keeps the iNES header intact, so it loads normally in any NES emulator.

Patch an NES ROM now

Mistakes That Trip Up NES Patching

Using a ROM with a non-standard or stripped header

NES ROMs typically carry a small iNES header identifying the cartridge's mapper and layout. A ROM missing or altering that header can behave unpredictably once patched.

Applying a patch built for a different mapper or region

Two NES cartridges of "the same game" sometimes used different hardware mappers between regions. Match the patch to the exact version it lists.

Expecting the patch to flag a wrong ROM

IPS has no built-in verification. If the base ROM is wrong, the patch will still apply — just incorrectly.

Troubleshooting

Screen is garbled or the game resets constantly

A classic sign the base ROM didn't match the patch. Since IPS can't verify this beforehand, check the exact revision and mapper the hack expects.

Learn more

Emulator doesn't recognize the patched file at all

Confirm the file still starts with a valid iNES header — some tools strip or rewrite it unexpectedly when handling older ROM formats.

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Patch applies cleanly but graphics are missing

That points to a mapper mismatch rather than a patching failure — the ROM's hardware bank layout doesn't match what the hack assumes.

Learn more

FAQ

IPS was created during the earliest era of ROM hacking, when NES and SNES translation projects were some of the only ones happening. It's stuck around ever since as the format's home turf.
A short block at the start of most NES ROM files that describes the cartridge's mapper and memory layout. Patchers and emulators both read it to know how to handle the rest of the file.
Rarely — NES ROMs are small by nearly any modern patch format's standards, so size limits that matter on bigger platforms don't come up here.
Patching only changes the game file itself. Save data tied to your emulator is stored separately and isn't affected by applying a patch.

Related Guides

ROM PatcherPatch a ROM file directly in your browser.IPS PatcherA closer look at the format behind almost every NES patch.SNES ROM PatcherIPS's other classic home platform, from the same hacking era.TroubleshootingFix common ROM patching errors and mismatches.

Old format, same modern privacy guarantee — your ROM and patch stay on this device.

Open the ROM Patcher

Want more detail on the format itself? See the IPS patcher guide.

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