# Comparing Models
There are two ways to compare models. The option 'Model | Checking Tools | Compare with Reference Model…' prompts for a reference model and then lists some aspects that are different to the current model:
- Titles
- Specification
- Grid lines
- Planes
- Polylines
- Nodes
- Elements
- Members
- Sections
- 2D Properties
- 3D Properties
- Spring Properties
- Link Properties
It does not list what the differences are, only that there are additions, modifications, or deletions.
The recommended method for finding the differences between two versions of the same structure is to use the “File | Export | Input Data (GWA file)” menu command to save the input data for each model in GWA format. Then use a proprietary file-difference analysis tool such as CSDiff to highlight the differences. (At the time of writing, CSDiff is available as a free download.)