Supported File Formats


The COMSOL Model file type, with the extension .mph, is the default file type containing the entire model tree and application tree from the Model Builder and Application Builder, respectively. The file contains both binary and text data. The mesh and solution data is 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 that can be imported directly to the Geometry or Mesh nodes in the model tree.

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

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


The CAD Import Module and Design Module allow 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 do not require any add-on products. Unless noted otherwise in the table below, import of the listed file types is available on all supported versions of Linux®, Mac OS X, and Windows® operating systems.

File Format Extension Import Export
AutoCAD®1,2,3 .dwg Yes Yes9
Inventor®1,2,3 .ipt,.iam Yes Yes9
NX®1,4 .prt Yes No
PTC® Creo® Parametric1,3 .prt,.asm Yes Yes9
PTC® Pro/ENGINEER®1,3 .prt,.asm Yes Yes9
Revit® Architecture3,5 .rvt Yes9 Yes9
Solid Edge®3,6 .par,.asm Yes9 Yes9
SOLIDWORKS®1,2,3 .sldprt,.sldasm Yes Yes9
DXF (3D1,2 and 2D) .dxf Yes Yes10
Parasolid®1 .x_t,.xmt_txt,.x_b,.xmt_bin Yes Yes
ACIS®1 .sat,.sab,.asat,.asab Yes Yes
STEP1 .step,.stp Yes No
IGES1 .iges,.igs Yes No
CATIA® V52,7 .CATPart,.CATProduct Yes No
VRML, v18 .vrml,.wrl Yes No
STL8 .stl Yes Yes

1 Requires one of the LiveLink™ products for AutoCAD®, Revit®, PTC® Creo® Parametric™, Inventor®, PTC® Pro/ENGINEER®, Solid Edge®, SOLIDWORKS®, CAD Import Module, or Design Module
2Import supported on Windows® operating systems only
3Synchronization of files between COMSOL Multiphysics and a linked CAD program supported on Windows® 7, 8, and 8.1 operating systems only
4Import supported on Windows® and Linux operating systems only
5Requires LiveLink™ for Revit®
6Requires LiveLink™ for Solid Edge®
77Requires the CAD Import Module (or the Design Module or one of the LiveLink™ products for AutoCAD®, PTC® Creo® Parametric™, Inventor®, PTC Pro/ENGINEER®, Solid Edge®, or SOLIDWORKS®) and the File Import for CATIA® V5
8Limited to a single geometric domain
9From/To file using linked CAD package, provided the original CAD geometry is created in the CAD package
10Writing to file is supported for 2D geometry only


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, in the model tree.

File Format Extension Read Write
NETEX-G1 .asc Yes No
ODB++1 .zip,.tar,.tgz,.tar.gz Yes No
ODB++(X)1 .xml Yes No
GDS1 .gds Yes No
Touchstone2 .s2p, .s3p, .s4p, ... No Yes
SPICE Circuit Netlist3 .cir Yes No

1Requires the ECAD Import Module
2Requires one of the AC/DC Module, RF Module, MEMS Module, or Wave Optics Module
3Requires one of the AC/DC Module, RF Module, MEMS Module, Plasma Module, or Semiconductor Module

Material Databases

The Chemical Reaction Engineering Module and the Plasma 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®1 .dat, .txt, .inp3 Yes No
CAPE-OPEN (direct connection)1 n/a N/A N/A
LXCAT file2 .lxcat,.txt Yes No

1 Any file format is allowed, these are the most common extensions
2Requires the Plasma Module
3Any extension is allowed; These are the most common extensions


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, 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
STL .stl Yes Yes
VRML, v1 .vrml, .wrl Yes No
VTK .vtu No Yes

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
Adobe® Flash® .swf No Yes
Animated GIF .gif No Yes
AVI1 .avi No Yes
BMP .bmp Yes Yes
EPS (1D graphs) .eps No Yes
GIF .gif Yes Yes
JPEG .jpg, .jpeg Yes Yes
MP42 .mp4 Yes No
OGV2 .ogv Yes No
PNG .png Yes Yes
TIFF .tif, .tiff No Yes
WEBM2 .webm Yes No

1Available for Windows only

2Available in the Application Builder, for Windows® only, in the video form object

Programming Languages and Spreadsheet

Model files for Java® are editable files with the extension .java that contain sequences of COMSOL 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. Program code used in model files for Java® is essentially identical to that of the Method editor in the Application Builder. However, the Method editor comes with an integrated Java® compiler.

Model files for MATLAB® are editable script files (M files), similar to the model files for Java®, for use with MATLAB®. These model files, which have the extension .m, contain a sequence of COMSOL commands as a MATLAB® M file. You can run the model files in MATLAB® like any other M file scripts. It is also possible to edit the files in a text editor to include additional COMSOL commands or general MATLAB® commands. Running model files in the M file format requires LiveLink™ for MATLAB®.

With a license for LiveLink™ for Excel®, you can save models on the Visual Basic for Applications (VBA) format for use with Excel®.

Complied C-code can be linked with a model or application in several ways including the External Material and External Function interfaces in the Model Builder and as the External Library interface in the Application Builder.

File Format Extension Read Write
MATLAB®: Model file for MATLAB® .m No Yes
MATLAB®: Function1 .m Yes No
Java®: Archive File .jar6 Yes No
Java®: Compiled model file for Java® .class Yes No
Java®: Model file for Java® .java No Yes
C: Function .dll3, .so4, .dylib5 Yes No
Excel®2 .xlsx,.vba Yes Yes

1Requires LiveLink™ for MATLAB®
2Requires LiveLink™ for Excel®, available for Windows® only
3Available for Windows® only
4Available for Linux® only
5Available for Mac OS X only
6Can be linked to a method in an application using the Application Builder

Numerical and 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
Excel® spreadsheet1 .xlsx 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
Point data for Cut Point data sets .txt Yes No
DEM .dem Yes No
VTK .vtu No Yes

1Requires LiveLink for Excel®, available for Windows® only