File size can impact SketchUp’s performance. Each entity you create, and each enhancement you apply to those entities, adds to the size of your file. Even when you delete entities you aren’t using, their definition stays in your model, creating what is called model bloat.

If you are experiencing performance issues, SketchUp’s Purge Unused feature can help you remove the bloat from your model. To activate Purge Unused:

1. Click Window > Model Info
2. Open the Statistics tab
3. At the bottom of the window, click Purge Unused

In SketchUp 2025 and any newer version, SketchUp will ask you if you want to purge unused entities each time you manually save your model by default. You can control this setting in the General tab of Preferences.

The easiest way to deal with bloat is to model efficiently with bloat in mind. Here’s a few causes of model bloat, along with a few best practices to prevent it:

• Materials and Environments – Any materials you apply to entities in your model stay there even if you decide not to use them. High resolution materials, or materials with complex textures, can really slow your model down. As you model, reuse materials and textures where you can, and reduce the resolution of the images you import.
• Imported Components – Make a note of the file size and edge count of components you import into your model. If you are importing from 3D Warehouse, these values are listed in the model’s description. When searching, you can often find multiple options for the same type of model with less complexity.
• Complex Entities – When creating entities, try to use the minimum number of polygons required to communicate your design. Reducing segments on arcs and circles is the easiest way to reduce your polygon count.
• Complex 3D Text – Some fonts require a very high edge count when used as 3D text. Use plain, sans serif fonts if possible.

For more tips like this, see Improving Performance.