ROM Patcher vs UniPatcher

ROM Patcher is a free browser tool that applies patch files to a user's legally dumped game backup and produces a modified ROM. Common uses include fan translations, bug fixes and ROM hacks. It supports IPS, UPS, BPS, xdelta, APS, PPF and RUP formats, and the site includes a Pokémon-focused patching guide. No installation or account is needed. ROM and patch files are processed in the browser rather than uploaded, stored or transmitted by the service; the resulting ROM is generated there and offered as a local download. Patching runs in a Web Worker so the page does not freeze when handling large ROM files. The site does not provide ROMs, so users need to supply their own legally dumped backups. Verification differs by format: UPS checks source and result ROMs with CRC32, while BPS checks the source, target and patch. IPS is limited to files smaller than approximately 16 MB and has no built-in checksum, so using the wrong ROM can silently corrupt it. The patched output can be loaded in an emulator of the user's choice. The maker describes the rest of the site as an early, growing preview.

UniPatcher is a free Android app for applying patches to ROMs from older console games, rather than native Android games. Users select a ROM, choose a patch, specify an output file, and start the operation with the round button through the Files app or another file manager. Supported formats include IPS, IPS32, UPS, BPS, APS for GBA and N64, PPF, DPS, EBP, and XDelta3. The app can create XDelta patches, repair checksums in SMD or Genesis ROMs, and remove SMC headers from SNES ROMs. Compressed games and patches in ZIP, RAR, or 7z format must be unzipped first. The project is licensed under GPL version 3. Its privacy policy says the app does not collect or transmit personally identifiable or location data and does not share personal information with advertisers, vendors, or analytics providers. Google Play reports no data collected or shared with third parties. Boris Timofeev is listed as developer. Bug reports use GitHub Issues, while questions and feature suggestions use GitHub Discussions; translation contributions go through Weblate.