# marcrobledo/RomPatcher.js

An IPS/UPS/APS/BPS/RUP/PPF/xdelta ROM patcher made in HTML5.

Repository: https://github.com/marcrobledo/RomPatcher.js
Canonical: https://ross.abutalabs.com/products/rompatcherjs
Homepage: https://www.marcrobledo.com/RomPatcher.js/
Language: JavaScript
License: NOASSERTION
License Family: other
Topics: patcher, rom, romhacking, ips, ups
Last push: 2026-07-11T10:40:21+00:00

## Health v2 (maintenance only)
Score: 69/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 92, release rhythm 23, longevity 100
- inputs: {"age_days": 3459, "days_push": 53, "days_rel": 302, "gap_med": 367, "n_releases_24m": 2}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1181, forks 187 (observed 2026-08-28T04:03:54.149893+00:00)

## What it is
A browser-based and Node.js ROM patcher supporting many patch formats (IPS, UPS, APS, BPS, RUP, PPF, EBP, BSDiff, xdelta/VCDiff, and more). It can both apply and create patches, and can be embedded into websites to offer an online patcher.

## Use cases
- apply an IPS patch to a ROM in the browser
- create a BPS patch from original and modified ROMs
- embed an online patcher on a romhacking site so users patch without downloads
- patch ROMs from a Node.js CLI script
- check a ROM's CRC32/MD5/SHA-1 before patching
- remove ROM headers before applying patches
- automatically unzip ROM files before patching

## When to choose
- you need to apply or create ROM patches in many formats without installing native tools
- you run a romhack distribution site and want users to patch ROMs online
- you want a lightweight vanilla-JS patcher that also works in Node.js

## When to avoid
- you need to patch formats not in the supported list
- you need a native desktop application with deep ROM editing features beyond patching

## Facets
- artifact type: application
- maturity: stable
- function: file-system, cli, developer-tools
- domain: gaming-tools, files, web-development
- platform: browser, cli, cross-platform
- tags: rom-patcher, romhacking, ips, ups, bps, ppf, xdelta, vanilla-js, embeddable, nodejs, web-server

## Member repositories
- marcrobledo/RomPatcher.js (main) score 69

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:54.149893+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:25:12.257360+00:00, confidence not recorded.
  - readme: https://github.com/marcrobledo/RomPatcher.js (fetched 2026-08-28T04:03:54.149893+00:00, sha fa4d7f03b7c0)
  - homepage: https://www.marcrobledo.com/RomPatcher.js/ (fetched 2026-08-29T12:31:57.371269+00:00, sha fbcd97bcf872)
- Data as of 2026-08-30T08:39:29.467469+00:00.