AutoCAD 2007 was the Wild West of third-party add-ons (like CADopia or early Revit converters). When you save a file, it stores "proxy graphics" for objects it doesn't recognize. These are essentially heavy PNG images hidden inside your vector file.
The original ACAD2007.exe was a 32-bit application. It could theoretically reference files up to 2 GB, but in practice, it would crash catastrophically once a file exceeded 150 MB . Why Are Your Old 2007 Files So Bloated? If you open a 2007 file today in AutoCAD 2025 and run -PURGE > Regapps , you will likely lose 50% of the file weight immediately. Here is why: autocad 2007 file size
A 3D model saved in AutoCAD 2007 is often 30-50% larger than the same model saved in AutoCAD 2010 or later. What is a "Normal" File Size for 2007? There is no single answer, but based on industry standards from that era, here is the rule of thumb: AutoCAD 2007 was the Wild West of third-party