Supported File Formats


The COMSOL Model filetype, with the extension .mph, is the default file type containing the entire Model Tree. The file contains both binary and text data.The mesh and solution data are stored as binary data while all other information is stored as plain text.

The COMSOL binary and text file types, with the extension .mphbin and .mphtxt respectively, contain either geometry objects or mesh objects which can be imported directly to the Geometry or Mesh branches in the Model Tree.

The Physics Builder file type with the extension .mphphb, contains one or more physics user interfaces that you can access from the Model Wizard.

File Format Extension Read Write
COMSOL Model .mph Yes Yes
Application Builder .mphapp Yes Yes
Binary Data .mphbin Yes Yes
Text Data .mphtxt Yes Yes
Physics Builder .mphphb Yes Yes


The CAD Import Module allows for import of a range of industry-standard CAD file types. Additional file types are available through the bidirectional functionality of the LiveLink products for CAD as well as with the File Import for CATIA® V5 add-on.

The DXF (2D), VRML (3D), and STL (3D) file types are available for import with COMSOL Multiphysics® and don’t require any add-on products.

File Format Extension Version Import Export
AutoCAD® DXF(2D) .dxf up to R14 Yes Yes
DEM .dem - Yes No
STL1 .stl - Yes Yes
VRML1 .vrml, .wrl v1 Yes No

1Limited functionality for a single geometric domain only

File Format Extension Version Import Export
ACIS® .sat, .sab, .asat, .asab ACIS: up to R25, 2016 1.0 Yes Yes
AutoCAD® .dwg 2.5-2016 Yes No
AutoCAD® DXF .dxf 2.5-2016 Yes No
CATIA® V5 .CATPart, .CATProduct R8-R25, 2016 Yes No
IGES .igs, .iges up to 5.3 Yes No
Inventor® assemblies .iam 11, 2008-2016 Yes No
Inventor® parts .ipt 6-11, 2008-2016 Yes No
NX® .prt up to 10 Yes No
Parasolid® .x_t, .xmt_txt, .x_b, .xmt_bin up to V28.1 Yes Yes
PTC® Creo® Parametric™ .prt, .asm 1.0-3.0 Yes No
PTC® Pro/ENGINEER® .prt, .asm 16 to Wildifire 5.0 Yes No
SOLIDWORKS® .sldprt, .sldasm 98-2016 Yes No
STEP .step AP203, AP214 Yes No


The ECAD Import Module allows for import of 2D layout files with automatic conversion to 3D CAD models. The Touchstone file type is used for exporting S-parameters, impedance, and admittance values from simultaneous port and frequency sweeps. The SPICE Circuit Netlist file type is converted at import to a series of lumped circuit element nodes under an Electrical Circuit node.

File Format Extension Read Write
NETEX-G1 .asc Yes No
ODB++1 .zip, .tar, .tgz, .gz, .Z Yes No
ODB++(X)1 .xml Yes No
GDS II1 .gds Yes No
Touchstone .s2p, .s3p, .s4p, ... No Yes
SPICE Circuit Netlist2 .cir Yes No

1Requires the ECAD Import Module
2Requires one of the AC/DC, RF, MEMS, or Plasma Modules

Material Databases

The Chemical Reaction Engineering Module can read CHEMKIN® files to simulate complex chemical reactions in the gas phase. The Plasma Module can read LXCAT files for sets of electron impact collision cross-sections.

File Format Extension Read Write
CHEMKIN® .dat, .txt, .inp3 Yes No

1 Any file format is allowed, these are the most common extensions

Numerical Data, Images, and Movies

Results visualization can be exported to a number of common image file types, see the table below. Images can also be read and used as interpolation functions for physics modeling. Animations can be exported to one of the Animated GIF, Adobe® Flash®, and AVI file types.

File Format Extension Read Write
JPEG .jpg, .jpeg Yes Yes
PNG .png Yes Yes
BMP .bmp Yes Yes
.tif, .tiff .tif, .tiff No Yes
GIF .gif Yes Yes
EPS (1D graphs) .eps No Yes
Animated GIF .gif No Yes
Adobe® Flash® .swf No Yes
AVI1 .avi No Yes

1Available for Windows only

Interpolation Data Formats

The Grid, Sectionwise, and Spreadsheet file types can be read for defining Interpolation functions. The Sectionwise and Spreadsheet file types can furthermore be read and used for defining Interpolation curves and written for exporting Results. In addition, Tables can be copy-pasted on spreadsheet format.

Parameters and Variables can be imported and exported to the Plain text, Comma-separated values, or Data file types.

The Continuous and Discrete color table text file types are used for user-defined color tables for Results visualization.

Digital Elevation Model (DEM) files can be read and used as a Parametric Surface for defining a Geometry.

File Format Extension Read Write
Copy and paste spreadsheet format n/a Yes Yes
Table .txt, .csv, .dat Yes Yes
Grid .txt Yes Yes
Sectionwise .txt, .csv, .dat Yes Yes
Spreadsheet .txt, .csv, .dat Yes Yes
Parameters .txt, .csv, .dat Yes Yes
Variables .txt, .csv, .dat Yes Yes
Continuous and Discrete color table .txt Yes No
DEM .dem Yes No


The NASTRAN® Bulk Data file types are used to import a volumetric mesh. The VRML and STL file types are used to import a triangular surface mesh, and cannot be used for creating a volumetric mesh. If imported as a Geometry, then VRML and STL files can be used as a basis for creating a volumetric mesh for a single geometric domain.

File Format Extension Read Write
NASTRAN® Bulk Data .nas, .bdf, .nastran, .dat Yes Yes
VRML, v1 .vrml, .wrl Yes No
STL .stl Yes Yes

Programming Languages

Model Java® files are editable script files, with the extension .java, that contain sequences of COMSOL Multiphysics commands as Java® code. Edit the files in a text editor to add additional commands. You can compile these Java® files into Java® Class files, with the extension .class, and run them as separate applications.

Model M-files are editable script files, similar to the Model Java® files, for use with MATLAB®. Model M-files, which have the extension .m, contain a sequence of COMSOL Multiphysics commands as a MATLAB® M-file. Run the Model M-files in MATLAB® like any other M-file scripts. Also edit the files in a text editor to include additional COMSOL Multiphysics commands or general MATLAB® commands. Running files in the Model M-file format requires the LiveLink™ for MATLAB®.

File Format Extension Read Write
MATLAB®: Model M-File .m No Yes
Java®: Model Java® File .java No Yes
Java®: Model Class File .class Yes No
C: Function .dll1, .so2, .dylib3 Yes No

1Available for Windows® only
2Available for Linux® only
3Available for Mac OS X only