How to reduce the size of a DWG file in AutoCAD

Use the following commands to reduce the size of a DWG file.

1. Detach all unneeded xref files using the XREF command.
2. Select all objects in a drawing and enter the OVERKILL command. This could be needed more than once.
3. Enter the -PURGE command and choose Regapps.
4. Enter the PURGE command and select all options.
5. Enter the -SCALELISTEDIT command and reset the scale list.
6. Enter the FILTERS command and delete layer filters.
7. Use SAVEAS to save a new file or save overtop of the original.

Additional workflows:

• Use the WBLOCK command to resave parts or the entire drawing (see Export objects to a drawing file with WBLOCK command).
• Use the BLOCK command to combine and replace repeating objects or groups of line segments.
• Use the JOIN command to combine small line segments. 
• Divide a large drawing into multiple smaller drawings and then attach them into a master drawing (see About Attaching and Detaching Referenced Drawings (Xrefs)). Child drawings can then be loaded/unloaded from the parent drawing as needed.
• Use EXPORTLAYOUT to save layouts to new model space drawings.

Note: The amount of data in a drawing (used and unused), object types, and complexity all attribute to the size of a DWG file. Some drawings may not reduce very much in size while others may show a significant change.