# UndertaleModTool

> Browse and modify supported GameMaker data files, extract assets, and decompile or compile GML VM code. Includes room editing, scripted changes, a CLI, and the reusable UndertaleModLib library.

- Type: Tool
- Targets: Game
- Category: Game analysis tools
- Relationship: Foundation tool
- Sources reviewed: 2026-10-16
- Added to the catalog: 2026-10-16
- Original resource: <https://github.com/UnderminersTeam/UndertaleModTool>
- Primary source: <https://github.com/UnderminersTeam/UndertaleModTool/blob/f43e12c445c37d50dc6244caa12ccab232983f3f/README.md>
- Catalog page: <https://awesomerea.org/resources/undertalemodtool/>
- Record JSON: <https://awesomerea.org/resources/undertalemodtool/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/undertalemodtool/index.md)

## Requirements & limits

- Supply a supported game data file such as data.win, game.ios, or game.unx. Stable 0.9.2.0 provides a 64-bit Windows GUI and CLI packages for Windows, Ubuntu, and macOS.
- GML VM code editing excludes YYC, and some language features remain unsupported. Building the reviewed source requires the .NET 10 SDK or later and recursive submodules; the GUI build requires Windows.

## Primary sources

1. <https://github.com/UnderminersTeam/UndertaleModTool/blob/f43e12c445c37d50dc6244caa12ccab232983f3f/README.md>
2. <https://github.com/UnderminersTeam/UndertaleModTool/releases/tag/0.9.2.0>

## More in Games

- [frida-il2cpp-bridge](https://awesomerea.org/resources/frida-il2cpp-bridge/index.md) · Tool
- [objdiff](https://awesomerea.org/resources/objdiff/index.md) · Tool
- [decomp-permuter](https://awesomerea.org/resources/decomp-permuter/index.md) · Tool
- [asm-differ](https://awesomerea.org/resources/asm-differ/index.md) · Tool
- [UE Explorer](https://awesomerea.org/resources/ue-explorer/index.md) · Tool
- [GARbro](https://awesomerea.org/resources/garbro/index.md) · Tool

## 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.