GameMaker Decompiler Online
data.win, game.unx, game.ios or an Android APK — back to readable GML.
How It Works
Detect
The FORM chunk table is checked for GameMaker's GEN8 marker, so ordinary IFF and AIFF files are not misidentified.
Decompile
Each top-level CODE entry is converted from GameMaker VM bytecode into a browsable .gml file.
Browse
Open scripts and object events in the browser, inspect strings, or download the complete result as a ZIP.
What to Upload
GameMaker Studio ships the whole game in one archive. On Windows it is normally data.win, beside the game's executable. Linux builds use game.unx, macOS builds use game.ios, and Android stores the same format as assets/game.droid inside the APK. The name is not trusted: the archive is identified from its chunk structure.
If you have an Android build, upload the APK itself. A normal APK decompiler only shows the Java activity that starts GameMaker's runner. This decompiler keeps that Java and smali output intact and adds a gamemaker/ folder containing the actual game code.
What You Get Back
code/— one readable GML file for every recoverable script, object event, room creation handler and global code entry.strings/strings.txt— the contents of the archive's STRG table, including dialog, asset names, URLs and other embedded text.DECOMPILATION-NOTES.txt— the detected bytecode version and a plain-language explanation when the game uses YYC or a newer unsupported format.gamemaker/— the three items above live here for an APK, next to the Android wrapper'sresources/,sources/andsmali/.
VM Builds Versus YYC
GameMaker has two compilation backends. The normal VM backend stores GML as bytecode in the archive's CODE chunk. That bytecode keeps functions, variables, constants and control flow, so it decompiles into useful source. This is the format used by many well-known GameMaker desktop games and by VM Android exports.
YYC is different: the YoYo Compiler translates GML into C++ and then native machine code. A YYC archive has no CODE chunk because the program is in the executable or libyoyo.so. When that is detected, the result explains the limitation immediately instead of running a tool that can only produce an empty folder.
Limits
- Comments and layout are gone. The compiler does not store them, so reconstructed GML is reformatted.
- Compiler-generated code appears. Recent GameMaker releases lower constructors, closures and some language features into helper entries that may look less natural than the original source.
- Very new releases can lag. The result note names the detected GEN8 and bytecode versions when the installed decompiler cannot read an archive yet.
- YYC method bodies are native. They require a machine-code disassembler and cannot be reconstructed as GML by a bytecode decompiler.
- Downloaded content is absent. Anything fetched after the game starts was never present in the uploaded archive.
Frequently Asked Questions
Can data.win really become GML again?
Yes for VM builds. Names, constants and program structure survive in the CODE bytecode; only comments and exact formatting are permanently lost.
Where do I find data.win?
Open the installed game folder and look beside the executable. Steam games usually place it under steamapps/common/<game>/data.win.
Can I upload an APK directly?
Yes. Its assets/game.droid archive is extracted and decompiled automatically while the normal Android wrapper output is preserved.
Why did I get a YYC note?
The developer selected native compilation. There is no GML bytecode in that build, so a GML decompiler has nothing to read.
Does this execute the game?
No. The upload is read only as an archive. No executable content from it is launched.