Learning Center

How to Reduce the Size of Your Model File


There are several things you can do to reduce the size of your COMSOL Multiphysics® model file. Here, we outline a few of the different ways, including the steps that you can employ to do this.

Update Your Preferences

COMSOL Multiphysics® saves files in either a compressed or uncompressed state. You can switch between these two options by updating your preference settings by going to: File Menu > Preferences.

The File menu in COMSOL Multiphysics with the Preferences option selected.

Accessing the preferences through the File menu.

Under Preferences > Save you can change the Optimize MPH-files for setting to File size. All subsequent save operations will compress the file. This is not the default setting in the preferences because compressing will make save operations take a little more time.

A screenshot of the Preferences window with the Save menu selected to show the options for optimizing saving COMSOL application files.

The Preferences window, wherein the selections have been updated to the recommended settings to reduce the model file size upon saving.

In earlier versions of COMSOL Multiphysics, you can find this setting under Files and in the section of settings titled Saving COMSOL application files, change the Optimize for drop-down menu selection to File size.

A screenshot of the Preferences window with the Files menu expanded to show the options for saving COMSOL application files as either compressed or uncompressed.

The Preferences window for earlier versions of COMSOL Multiphysics, where you can update the setting for saved model files.

Clear the Mesh and Solution

If you do not need to keep the results in your model, but only want to save the unsolved model, you can use the Clear Built Mesh button in the Mesh ribbon tab or right-click on the Mesh node within the Model Builder window and select Clear Built Mesh. This removes the mesh data and keeps the information about how the mesh was created.

A screenshot of part of the Mesh ribbon in the Model Builder, with the Clear Built Mesh button selected and the Clear All Meshes and Delete Sequence buttons also shown.

The Clear Built Mesh button available in the Mesh ribbon tab.

A screenshot of the settings for the Mesh node, with the menu expanded and Clear Mesh option selected.

The Clear Built Mesh function accessed through right-clicking the Mesh node.

Similarly, you can use the Clear Solutions button in the Study ribbon tab or right-click on the Study node and select Clear Solutions. This removes the solution data, but keeps the solver information about how the solution was computed. Re-solving the model will recreate the same mesh and solution data.

A screenshot of part of the Study ribbon tab in the Model Builder, with the Clear Solutions button selected and the Clear All Solutions button also shown.

The Clear Solutions button available in the Study ribbon tab.

A screenshot of the Study Settings window with the menu expanded and the Clear Solutions option selected.

The Clear function accessed through right-clicking the Study node.

Reduce the Amount of Solution Data

File sizes can become significant when a lot of solution data is generated. Thus, you may want to reduce the amount of solution data contained in your model. If you want to keep some, but not all, of the solution data in your model, see our Learning Center article on reducing the amount of data stored in a model. You can follow the steps in the link provided, which will also help reduce the size of your COMSOL Multiphysics® model file.


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