# asm-differ

> Diffs original and rebuilt assembly for one function or ROM address to guide matching decompilation; its watch mode can rerun make when sources change. The README describes it as decomp.me’s default diff viewer and points to objdiff as a modern alternative.

- Type: Tool
- Targets: Binary · Game
- Category: Game analysis tools
- Relationship: Foundation tool
- Sources reviewed: 2026-10-17
- Added to the catalog: 2026-10-17
- Original resource: <https://github.com/simonlindholm/asm-differ>
- Primary source: <https://github.com/simonlindholm/asm-differ/blob/0dd09af8f8008f1f880327cf0aca3b26d2562ea2/README.md>
- Catalog page: <https://awesomerea.org/resources/asm-differ/>
- Record JSON: <https://awesomerea.org/resources/asm-differ/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/asm-differ/index.md)

## Requirements & limits

- Each project needs a diff_settings.py naming the original and rebuilt images and linker map; object-file mode compares against references in an expected/ directory. Requires Python 3 with colorama, watchdog, levenshtein and cxxfilt, plus an objdump for the target.
- The README lists MIPS, PPC, AArch64, ARM32, SH2, SH4, m68k and limited x86. Install it as a submodule, by copying diff.py or with pip from Git; there is no packaged release. Last commit at review: 2026-09-06.
- Released under the Unlicense. It shows instruction-level differences only and does not recover names, types or semantics.

## Primary sources

1. <https://github.com/simonlindholm/asm-differ/blob/0dd09af8f8008f1f880327cf0aca3b26d2562ea2/README.md>
2. <https://github.com/simonlindholm/asm-differ/blob/0dd09af8f8008f1f880327cf0aca3b26d2562ea2/LICENSE>
3. <https://github.com/simonlindholm/asm-differ/blob/0dd09af8f8008f1f880327cf0aca3b26d2562ea2/diff_settings.py>
4. <https://github.com/decompme/decomp.me/blob/6056cf56b3bf4f1cfcf2496fe97f83cc09b08010/frontend/src/lib/settings.ts#L55-L58>

## More in Games

- [UE Explorer](https://awesomerea.org/resources/ue-explorer/index.md) · Tool
- [GARbro](https://awesomerea.org/resources/garbro/index.md) · Tool
- [Godot RE Tools](https://awesomerea.org/resources/godot-re-tools/index.md) · Tool
- [UE4SS](https://awesomerea.org/resources/ue4ss/index.md) · Tool
- [FModel](https://awesomerea.org/resources/fmodel/index.md) · Tool
- [PSP Web Recomp](https://awesomerea.org/resources/psp-web-recomp/index.md) · Project

## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.