rom-weaver

Comparison with similar tools

rom-weaver overlaps with six established tools, each narrower than it is. This page compares all of them, format by format and feature by feature, so you can tell which one fits your job.

Legend

Every table on this page uses these three marks. Each one has its own shape as well as its own colour, so the tables still read without colour vision.

Mark Meaning
✅ Supported.
⚠️ Partly supported. The limit is written next to the mark, or in a numbered note under the table.
❌ Not supported.

The tools

Tool What it does Platforms License
rom-weaver ROM workflow: patch, extract, compress, hash, trim, bundle Browser, Linux, macOS, Windows AGPL-3.0-or-later
RomPatcher.js Applies and creates ROM patches Browser, Node MIT
Floating IPS (Flips) Applies and creates IPS and BPS patches Linux, macOS, Windows GPL-3.0
MultiPatch Applies and creates seven patch families macOS GPL-2.0
xdelta3 General VCDIFF delta compressor Linux, macOS, Windows Apache-2.0
chdman Converts disc images to and from CHD Linux, macOS, Windows GPL-2.0
Dolphin tool Converts GameCube and Wii images Linux, macOS, Windows GPL-2.0

The last three are the reference implementations rom-weaver is tested against. Its CHD and RVZ output is checked byte-for-byte against chdman and Dolphin tool, and its patch output against Flips and MultiPatch, so choosing rom-weaver for those jobs is a question of convenience, not of different bytes. The full list of specifications consulted is in references.

At a glance

The patch counts are format counts from the Applying a patch and Creating a patch tables, so every tool is counted the same way. Partial support counts. A row naming several formats counts as each of them.

Capability rom-weaver RomPatcher.js Flips MultiPatch xdelta3 chdman Dolphin tool
Patch formats applied ✅ 21 ⚠️ 12 ❌ 3 ⚠️ 8 ❌ 2 1 ❌ 2 ❌ 2
Patch formats created ✅ 18 ⚠️ 7 ❌ 2 ⚠️ 7 ❌ 2 1 ❌ 2 ❌ 2
Chain several patches ✅ ❌ ❌ ❌ ❌ ❌ ❌
ROM header awareness ✅ 12 families ⚠️ 4 formats ⚠️ SNES only ❌ ❌ ❌ ❌
Archive extract ✅ 23 formats ⚠️ ZIP only ❌ ❌ ❌ ❌ ❌
Archive or image create ✅ 5 formats ❌ ❌ ❌ ❌ ⚠️ CHD only ⚠️ 4 formats
Standalone checksum tool ✅ 8 algorithms ⚠️ 3, display only ❌ ❌ ❌ ⚠️ CHD self-check ⚠️ image verify
Trim ROM padding ✅ ❌ ❌ ❌ ❌ ❌ ❌
Runs in a browser ✅ ✅ ❌ ❌ ❌ ❌ ❌
Command line ✅ ⚠️ Node script ✅ ⚠️ macOS only ✅ ✅ ✅

1 xdelta3's two rows, VCDIFF and xdelta, are one underlying family: plain VCDIFF. It is a general delta tool with no ROM knowledge at all — no headers, no byte order, no consoles.

2 chdman and Dolphin tool do not patch. They convert disc images.

Applying a patch

rom-weaver reads 21 patch formats. No other tool here reads more than 12.

Format rom-weaver RomPatcher.js Flips MultiPatch xdelta3
IPS ✅ ✅ ✅ ✅ ❌
IPS32 ✅ ❌ ❌ ❌ ❌
EBP ✅ ✅ ❌ ❌ ❌
BPS ✅ ✅ ✅ ✅ ❌
UPS ✅ ✅ ✅ ✅ ❌
PPF ✅ ✅ ❌ ✅ ❌
RUP ✅ ✅ ❌ ✅ ❌
APS (N64) ✅ ✅ ❌ ❌ ❌
APSGBA ✅ ✅ ❌ ❌ ❌
BDF/BSDIFF40 ✅ ✅ ❌ ✅ ❌
MOD (PMSR) ✅ ✅ ❌ ❌ ❌
VCDIFF ✅ ⚠️ 1 ❌ ✅ 2 ✅
xdelta ✅ ⚠️ 1 ❌ ✅ 2 ✅
SOLID ✅ ❌ ❌ ❌ ❌
GDIFF ✅ ❌ ❌ ❌ ❌
PAT (FireFlower) ✅ ❌ ❌ ❌ ❌
DLDI ✅ ❌ ❌ ❌ ❌
DPS ✅ ❌ ❌ ❌ ❌
BSP ✅ ❌ ❌ ❌ ❌
HDiffPatch/HPatchZ ✅ ❌ ❌ ❌ ❌
DCP (Dreamcast) ✅ ❌ ❌ ❌ ❌

1 RomPatcher.js decodes plain VCDIFF but throws on two optional parts of the spec: a secondary compressor and a custom code table. Most .xdelta patches from xdelta3 use the djw secondary compressor, so they fail.

2 MultiPatch links the real xdelta3 library, so it decodes both. So does rom-weaver.

rom-weaver has gaps too. It detects NINJA1 headers but cannot apply them, it does not support PDS, and it does not support HDiffPatch directory patches (HDIFF19). None of the other tools support those either.

Creating a patch

Format rom-weaver RomPatcher.js Flips MultiPatch xdelta3
IPS ✅ ✅ ✅ ✅ ❌
IPS32 ✅ ❌ ❌ ❌ ❌
EBP ✅ ✅ ❌ ❌ ❌
BPS ✅ ✅ ✅ 1 ✅ ❌
UPS ✅ ✅ ❌ 2 ✅ ❌
PPF ✅ ✅ ❌ ✅ ❌
RUP ✅ ✅ ❌ ❌ ❌
APS (N64) ✅ ✅ ❌ ❌ ❌
APSGBA ✅ ❌ ❌ ❌ ❌
BDF/BSDIFF40 ✅ ❌ ❌ ✅ ❌
MOD (PMSR) ✅ ❌ ❌ ❌ ❌
VCDIFF ✅ ❌ ❌ ✅ ✅
xdelta ✅ ❌ ❌ ✅ ✅
SOLID, GDIFF, PAT, DLDI, DPS ✅ ❌ ❌ ❌ ❌
BSP, HDiffPatch, DCP ❌ ❌ ❌ ❌ ❌

1 Flips is the only tool here offering two BPS strategies on the command line: --bps-delta and --bps-linear.

2 Flips ships a UPS encoder in its library but exposes no way to reach it, so UPS is apply-only in practice.

Containers and disc images

Format rom-weaver extract rom-weaver create RomPatcher.js chdman Dolphin tool
ZIP ✅ ✅ ⚠️ extract only ❌ ❌
ZIPX ✅ ❌ ❌ ❌ ❌
7z ✅ ✅ ❌ ❌ ❌
RAR ✅ ❌ ❌ ❌ ❌
TAR (plain, gz, bz2, xz) ✅ ❌ ❌ ❌ ❌
Gzip, Bzip2, XZ, Zstandard ✅ ❌ ❌ ❌ ❌
CHD ✅ ✅ ❌ ✅ 1 ❌
RVZ ✅ ✅ ❌ ❌ ✅
Z3DS ✅ ✅ ❌ ❌ ❌
GCZ ✅ ❌ 2 ❌ ❌ ✅
WIA ✅ ❌ 2 ❌ ❌ ✅
TGC ✅ ❌ ❌ ❌ ⚠️ read only
NFS ✅ ❌ ❌ ❌ ⚠️ read only
WBFS ✅ ❌ ❌ ❌ ⚠️ read only
CSO/CISO ✅ ❌ ❌ ❌ ⚠️ read only
PBP ✅ ❌ ❌ ❌ ❌
XISO ✅ ❌ ❌ ❌ ❌

1 chdman also reads .cue, .gdi, .toc, and raw images as CHD build inputs, which is a different job from extracting an existing archive.

2 An honest gap: Dolphin tool writes GCZ and WIA, and rom-weaver only reads them.

The practical difference: rom-weaver can take a .chd or .rvz disc image, patch the ROM inside, and pack the result back up in one command. Every other tool here needs you to convert, patch, and convert back by hand.

Checksums

Capability rom-weaver RomPatcher.js Flips MultiPatch chdman Dolphin tool
Algorithms ✅ CRC32, CRC32C, CRC16, MD5, SHA-1, SHA-256, BLAKE3, Adler-32 ⚠️ CRC32, MD5, SHA-1 ❌ ❌ ⚠️ SHA-1 1 ⚠️ CRC32, MD5, SHA-1 1
Shows ROM hashes ✅ ✅ ❌ ❌ ❌ ❌
Verifies checksums in the patch ✅ ✅ ✅ ✅ ❌ ❌
Assert an expected input hash ✅ --expect-in ❌ ❌ ❌ ❌ ❌
Assert an expected output hash ✅ --expect-out ❌ ❌ ❌ ❌ ❌
Hash a byte range ✅ --start/--length ❌ ❌ ❌ ❌ ❌
Hash a file inside an archive ✅ ❌ ❌ ❌ ❌ ❌
Header and byte-order variants ✅ all detected headers, plus trim boundaries 2 ⚠️ N64 only ❌ ❌ ❌ ❌

1 chdman verify and Dolphin tool verify check an image against its own stored hashes. Neither hashes an arbitrary file.

2 This matters when a patch's readme lists a CRC32 you cannot reproduce. rom-weaver reports the hash of the raw file, the headerless file, the repaired-header file, and each N64 byte order at once, so you can see which one the author meant. See Fix a checksum error.

Headers and byte order

Behavior rom-weaver RomPatcher.js Flips MultiPatch
Header detection ✅ 12 families 1 ⚠️ 4 formats 2 ⚠️ SNES copier only 3 ❌
Checksum repair ✅ 12 platforms 4 ⚠️ Game Boy, Mega Drive ❌ ❌
Header strip mode ✅ auto, keep, or strip, per patch ⚠️ manual on/off ⚠️ auto-detect, --exact to force ❌
Output header mode ✅ separate auto, keep, or strip ⚠️ follows the input choice ⚠️ restores what it stripped ❌
N64 byte order ✅ converts to match the patch, writes back in the original order ⚠️ detects .z64 for its CRC display ❌ ❌

1 A78, LNX, NES and FDS, SNES copier and SMC variants, PCE copier formats, Game Boy and GBA, Mega Drive, SMS and Game Gear, all N64 byte orders, NDS, Neo Geo Pocket, and MSX.

2 iNES (.nes), fwNES (.fds), LNX (.lnx), and SNES copier (.sfc, .smc, .swc, .fig), picked by file extension and file size.

3 The 512-byte SNES copier header and nothing else.

4 SNES, NES, Game Boy/GBA, Mega Drive, SMS/Game Gear, N64, Atari 7800/Lynx, PCE/TurboGrafx-16, Virtual Boy, Neo Geo Pocket, MSX, and NDS. FDS, Atari Jaguar, ColecoVision, Watara Supervision, and Intellivision headers are validated but not rewritten.

Patching features

Feature rom-weaver RomPatcher.js Flips MultiPatch xdelta3
Apply one patch ✅ ✅ ✅ ✅ ✅
Chain several patches in order ✅ repeat --patch ❌ 1 ❌ 1 ❌ 1 ❌ 1
Validate without writing ✅ patch validate ❌ ⚠️ --info ❌ ⚠️ printhdr
Check each patch independently ✅ --independent ❌ ❌ ❌ ❌
Find patches beside the ROM in an archive ✅ ❌ ❌ ❌ ❌
Bake in Game Genie / GameShark codes ✅ --code ❌ ❌ ❌ ❌
Undo a PPF3 patch ✅ tools ppf-undo ❌ ❌ ❌ ❌
Override a failed checksum ✅ --ignore-checksum-validation ✅ ✅ --ignore-checksum ❌ ❌
Patch metadata on create ⚠️ SOLID fields only 2 ✅ RUP description, EBP JSON ✅ BPS manifest ❌ ✅ -A app header
Machine-readable output ✅ --json ❌ ❌ ❌ ❌

1 These apply exactly one patch per run. Hacks that ship a base patch plus an update need two passes, and you have to keep the intermediate file yourself.

2 --solid-system, --solid-game, --solid-hack, --solid-version, --solid-author, --solid-contact, and --solid-comment. RUP and EBP patches are written with an empty description and a placeholder JSON block respectively; neither can be set.

Beyond patching

Command rom-weaver Anything else here
Trim and restore ✅ NDS, GBA, 3DS, XISO, and RVZ scrub 1 ❌
Compress ✅ ZIP, 7z, CHD, RVZ, Z3DS ⚠️ chdman for CHD, Dolphin tool for RVZ/GCZ/WIA/ISO
Probe ✅ format, platform, and header, including from stdin ⚠️ chdman info, Dolphin tool header
Ingest ✅ sorts a mixed folder into ROMs and patches ❌
Bundles ✅ rom-weaver-bundle.json recipes 2 ❌

1 trim --revert pads a trimmed file back out for NDS, GBA, and 3DS, and --revert-marker stores a footer so that revert is exact rather than a guess at the padding. XISO and RVZ scrub are one-way.

2 A bundle records the ROM's checksums, the patch order, and the expected result, so someone else can reproduce your build. See What a bundle is.

Delivery and platforms

Property rom-weaver RomPatcher.js Flips MultiPatch xdelta3 chdman Dolphin tool
Browser ✅ WebAssembly ✅ plain JavaScript ❌ ❌ ❌ ❌ ❌
Command line ✅ native, 9 platforms ⚠️ Node script ✅ ⚠️ macOS only ✅ ✅ ✅
Desktop GUI ❌ ❌ ✅ GTK, Win32 ✅ Cocoa ❌ ❌ ❌
Embed in your own page ❌ ✅ a stated goal ❌ ❌ ❌ ❌ ❌
Multi-threaded ✅ -j sets the ceiling ⚠️ one worker per job ❌ ❌ ❌ ✅ ✅
Large files ✅ streams; disc images are normal ⚠️ warns above 64 MB 1 ✅ ✅ ✅ ✅ ✅
Install ✅ npm, Homebrew, Docker, or a binary ⚠️ copy files, or npm install ⚠️ binary or build ⚠️ app download ⚠️ package or build ⚠️ part of MAME tools ⚠️ part of Dolphin
Language Rust JavaScript C++ Objective-C, C++ C C++ C++

1 The warning is advisory, not a block. It reflects that RomPatcher.js loads whole files into JavaScript arrays.

Which one should you use?

RomPatcher.js when you are publishing a hack and want a patch button on your own site. It embeds in a page, has no build step, and handles IPS, BPS, or UPS on a cartridge ROM in a few kilobytes of script.

Flips when you only touch IPS and BPS and want the reference BPS encoder with both delta and linear strategies, plus a desktop GUI.

MultiPatch when you are on macOS and want a native app covering seven families, including real xdelta3.

xdelta3 when the files are not ROMs. It is a general delta compressor and knows nothing about headers, byte order, or consoles.

chdman or Dolphin tool when you want the reference converter itself, or need an output rom-weaver does not write — Dolphin tool writes GCZ and WIA.

rom-weaver when the job is bigger than one patch and one ROM: a disc image inside a CHD, an .xdelta patch with secondary compression, a chain of patches, an N64 ROM in the wrong byte order, a checksum you need to explain, or a scripted batch you want to run the same way twice.

These are not exclusive. Publishing a BPS patch with a RomPatcher.js button on your page, and a rom-weaver bundle for people who want the checksums recorded, covers both audiences.

How this page was checked

Every claim was read out of each tool's source or official documentation, not out of a feature list.

Tool Checked at What was read
rom-weaver 0.12.2 Supported formats, CLI reference
RomPatcher.js commit aef583b, v3.0.0 RomPatcher.js format registry and header logic, modules/ parsers, index.js CLI
Flips master flips.cpp patch identification and create paths, libips/libbps/libups, CLI options
MultiPatch master MPPatchWindow.mm apply dispatch, MPCreationWindow.mm create list, adapters/, XDeltaAdapter.m
xdelta3 master Command line syntax documentation
chdman current MAME docs The chdman command list
Dolphin tool master ToolMain.cpp subcommands, ConvertCommand.cpp output formats, Blob.cpp readable formats

All projects move. If a row here is stale, check the rom-weaver side against Supported formats, and each other tool's side against the repository linked from the tools.