Rework a cartridge, keep it yours.

Edit the Oak's lab starter and wild encounters, then download a BPS patch. Your ROM is uploaded to our server for transient in-memory processing to read it and build your patch; the server does not store or log it. If you choose Remember this ROM, a copy also stays in this browser on this device until you Forget it. Use only a ROM you own.

Verified starter presets are available only where listed; wild encounter editing works only on recognized ROMs, with untested areas labelled, and six-member starting parties are unavailable on most ROMs.