How to Reduce File Size

Purge Unused 

• Deleting things from the model doesn’t delete them from the model file.
• Go to Window>Model Info>Statistics>Purge Unused to get rid of deleted Components, Styles, Tags, and Materials. 
• Do it before every big save to reduce file size in SketchUp.

Purge Unused at save (from 2025)

Environments in 2025

To keep file size down when using Image-Based Lighting (IBL) environments in SketchUp 2025, consider the following strategies:

• Optimise Image Resolution: Use lower resolution images for your IBL environments. High-resolution images can significantly increase file size.
• Compress Images: Utilize image compression tools to reduce the file size without losing much quality. Formats like JPEG can be useful for this purpose.
• Limit the Number of IBLs: Use only the necessary number of IBL environments in your project. Each additional environment can add to the file size.
• Use External References: Instead of embedding the IBL images directly into your SketchUp file, reference them externally. This can help keep the SketchUp file size smaller.