Binary Data Files and Text Data Files A COMSOL Multiphysics file is used to store COMSOL data. The format is suitable for exchange of mesh or CAD data between COMSOL and other software systems. It is possible to save a COMSOL Multiphysics file in a text file format, using the extension .mphtxt, or a binary file format, using the extension .mphbin. The file formats contain the same data in the same order. In this section: • File Structure • Records • Terminology • Text File Format • Binary File Format