Click the "Select File" button above, and choose your S file.
You’ll see a preview, if available.
Click the "Convert file to..." button to extract text information.
Convert S to another file type
To convert S Assembly files to another format, you need GNU Assembler or other Developer software.
Convert a file to S
To convert other file formats to the "Source Code File" file type, you need software like GNU Assembler or a similar tool.
About S files
The .s file format is primarily associated with Assembly language source code. These are plain text files containing low-level programming instructions executed by a processor after being compiled by software like the GNU Assembler (as). Another common use is for Microsoft Train Simulator (MSTS), where .s files store 3D shape data for locomotives and scenery objects. For developers, raw assembly files are heavily hardware-dependent, making them difficult to read for non-programmers. For gamers and modders, MSTS shape files are stored in a proprietary, often compressed binary format that modern 3D editors like Blender cannot open directly without specialized decompression tools. Furthermore, some internal business systems incorrectly export standard reports with a .s extension when the underlying file is actually a PDF or ZIP archive. If you need to review assembly code without installing an IDE, convert .s to TXT or PDF for easy reading and archiving. If you are modifying train models, convert MSTS .s files to standard 3D formats like OBJ or FBX for editing, keeping in mind that complex animation data may be lost in the process.
Convert.Guru analyzes your S file, detects the exact format, and lets you read the text inside.
If you want to convert S file to H, HZ, OBJ, FBX, DAE, 3DS, MAX, BLEND, MA, MB, C4D or STL, you can use GNU Assembler or similar software from the "Assembly Source Code" category. In the File menu, look for Save As… or Export….
To convert DWG, DAE, X3D, IGES, WRL, JT, SKP, 3DS, 3DM, OBJ, STEP or FBX files to S, try GNU Assembler or another comparable tool in the "Assembly Source Code" category.
The S Converter Story
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our S converter.