About EZ ROM Patcher
EZ ROM Patcher is a free browser-based ROM patching tool built on Rom Patcher JS, the open-source MIT-licensed engine by Marc Robledo. All patching happens on your device. The engine is pulled directly from its GitHub repository and automatically verified before every deploy.
Credits
The patching engine is Rom Patcher JS by Marc Robledo, released under the MIT licence. It implements every patch format this site supports, and the work here is a wrapper around it rather than a reimplementation.
The checksum tool uses the CRC32 and MD5 implementations from Marc Robledo’s SFV Checker, also MIT-licensed. SHA-1 comes from the browser’s built-in Web Crypto API.
Rom Patcher JS also depends on zip.js by Gildas Lormeau for archive handling, and Octicons by GitHub for interface icons.
How this site stays current with upstream
The engine is not copied and forgotten. Every build fetches the latest source directly from the upstream GitHub repository, so improvements and new format support land here without a manual port.
That would be risky on its own, so each build runs an automated gate before anything ships. It round-trips real patches through the freshly fetched engine in seven formats, checks that hashes match standard test vectors, and confirms the APIs this site depends on still exist. If any check fails, the build stops rather than publishing a patcher that cannot patch.
What this site will not do
We do not host ROMs, link to ROM sites, or help you find copyrighted games. This is a file utility. Supplying the ROM is your responsibility, and dumping it from hardware you own is the lawful route.
Frequently asked questions
Is EZ ROM Patcher open source?
The patching engine is. Rom Patcher JS by Marc Robledo is MIT-licensed and available on GitHub, and this site vendors it unmodified apart from one path adjustment needed to run it inside a multi-page site.
How often is the patching engine updated?
Every build pulls the latest upstream source, so a deploy picks up whatever Marc Robledo has published. An automated verification gate runs first and blocks the build if the new version fails its round-trip patch tests.
Is this site affiliated with Marc Robledo?
No. It uses his MIT-licensed open-source engine with attribution, as the licence permits and the project’s documentation encourages, but it is an independent site.