Check the file header. Lua files usually start with the hex signature 1B 4C 75 61 . The byte following this indicates the version (e.g., 51 for 5.1).
Studying how professional developers structure their scripts in production environments. Challenges in Lua Decompilation lua decompiler
Recovering source code for a project where the original files were lost. Check the file header
If a script was compiled with the "strip" option, the decompiler won't know the names of local variables. You’ll see generic names like l_1_ or var0 . You’ll see generic names like l_1_ or var0
Checking third-party scripts for malicious behavior.
Lua has several versions (5.1, 5.2, 5.3, 5.4, and Luau). Bytecode is not cross-compatible between these versions. You must use a decompiler that matches the specific version of the Lua VM that compiled the script.
Use the command line to point the decompiler at your file: java -jar unluac.jar input_file.luac > output_file.lua