Learning Center

Supported File Formats

COMSOL Multiphysics® enables you to work with different file types, including:

  • CAD
  • ECAD
  • Material databases
  • Mesh
  • Images, movies and audio
  • Programming languages and spreadsheets
  • Numerical and interpolation data formats

You have the flexibility to edit and change designs created in third-party software. Here, we describe the import, export, and read and write capabilities of various file types within the software.

COMSOL Multiphysics®

The COMSOL Multiphysics® 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 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 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 Import Export
COMSOL model and application .mph Yes Yes
COMSOL binary data .mphbin Yes Yes
COMSOL text data .mphtxt Yes Yes
Physics Builder .mphphb Yes Yes


The CAD Import Module and Design Module allow for the 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 3MF (3D), DXF (2D), PLY (3D), 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®, macOS, and Windows® operating systems. For up-to-date information on supported platforms, visit our page on the system requirements.

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 Parametric™1,3 .prt, .asm Yes Yes9
Revit® Architecture3,5 .rvt Yes9 Yes9
Solid Edge®3,6 .par, .asm Yes9 Yes9
SOLIDWORKS®1,3,4 .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 Yes
IGES1 .iges, .igs Yes Yes
CATIA® V52,7 .CATPart, .CATProduct Yes No
VRML, v18 .vrml, .wrl Yes No
3MF .3mf Yes No
PLY .ply Yes No
STL .stl Yes Yes

1 Requires one of the LiveLink™ products for AutoCAD®, Revit®, PTC Creo Parametric™, Inventor®, Solid Edge®, SOLIDWORKS®, CAD Import Module, or Design Module.
2 Import supported on Windows® operating systems only.
3 Synchronization of files between COMSOL Multiphysics® and a linked CAD program supported on Windows® 10 and 11 operating systems only.
4 Import supported on Windows® and Linux operating systems only.
5 Requires LiveLink™ for Revit®.
6 Requires LiveLink™ for Solid Edge®.
7 Requires the CAD Import Module (or the Design Module or one of the LiveLink™ products for AutoCAD®, PTC Creo Parametric™, Inventor®, Revit®, Solid Edge®, or SOLIDWORKS®) and the File Import for CATIA® V5.
8 Limited to a single geometric domain.
9 From/To file using linked CAD package, provided the original CAD geometry is created in the CAD package.
10 Writing to file is supported for 2D geometry only.


The ECAD Import Module allows for the 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 Import Export
IPC-25811 .cvg, .xml Yes No
ODB++1 .zip, .tar, .tgz, .tar.gz Yes No
GDS1 .gds Yes No
Touchstone2 .s2p, .s3p, .s4p, ... No Yes
SPICE Circuit Netlist3 .cir Yes Yes

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

Material Databases

From the Materials node, in the model tree, you can import material data on the MPH-file format as well as on a COMSOL-native XML format. You can also export material data on the COMSOL-native XML format. When importing material data from an MPH-file, only the material contents of the file are considered. For exporting material data on the MPH-file format, you simply save the MPH-file using the options on the File menu.

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. The Metal Processing Module import material properties from the software JMatPro®.

File Format Extension Import Export
COMSOL model and application .mph Yes Yes
COMSOL model XML .xml Yes Yes
CHEMKIN®1 .dat, .txt, .inp3 Yes No
CAPE-OPEN (direct connection)1 N/A N/A N/A
LXCAT file2 .lxcat, .txt Yes No
JMatPro®4 .xml Yes No

1 Require the Chemical Reaction Engineering Module or the Plasma Module. The Plasma Module only supports thermodynamic and transport data.
2 Requires the Plasma Module.
3 Any extension is allowed; these are the most common extensions.
4 Requires the Metal Processing Module.


The NASTRAN® Bulk Data file types are used to import a volumetric mesh. The VRML, STL, PLY, and 3MF file types are used to import a triangular surface mesh that can serve as a starting point for creating a volumetric mesh.

File Format Extension Import Export
3MF .3mf Yes Yes
NASTRAN® Bulk Data .nas, .bdf, .nastran, .dat Yes Yes
PLY .ply Yes Yes
COMSOL sectionwise .txt, .csv, .dat Yes Yes
STL .stl Yes Yes
VRML, v1 .vrml, .wrl Yes No
VTK .vtu No Yes

Images, Movies, and Audio

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, AVI, and WebM file types. The 3D representation from a 3D plot can be exported to the glTF™ format for 3D scene exchange. Audio files can be imported and exported on the WAV audio file format.

File Format Extension Import Export
Animated GIF .gif No Yes
AVI1 .avi No Yes
BMP .bmp Yes Yes
EPS (1D graphs) .eps No Yes
GIF .gif Yes Yes
glTFTM .glb No Yes
JPEG .jpg, .jpeg Yes Yes
MP42 .mp4 Yes No
OGV2 .ogv Yes No
PNG .png Yes Yes
TIFF .tif, .tiff No Yes
WAV .wav Yes Yes
WebM2 .webm Yes2 Yes

1 Available for Windows® only.
2 Available 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 Import Export
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
Fortran7: function .dll3, .so4 Yes No
Excel®2 .xlsx, .vba Yes Yes

1 Requires LiveLink™ for MATLAB®.
2 Requires LiveLink™ for Excel®, available for Windows® only.
3 Available for Windows® only.
4 Available for Linux® only.
5 Available for macOS only.
6 Can be linked to a method in an application using the Application Builder.
7 Requires a C-wrapper to the Fortran code and to include the C-code DLL as an External C Library in the Application Builder. Alternatively, you can include a Fortran DLL directly as an External C Library in the Application Builder. Note: You need to consider the naming convention for exported Fortran function names. For example, in Windows®, it is typically required that Fortran function names are in uppercase.

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 the 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 Import Export
Copy-paste spreadsheet format N/A Yes Yes
Excel® spreadsheet1 .xlsx Yes Yes
Table .txt, .csv, .dat Yes Yes
Grid .txt Yes Yes
COMSOL sectionwise .txt, .csv, .dat Yes Yes
COMSOL 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 datasets .txt Yes No
DEM .dem Yes No
VTK .vtu No Yes

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

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