.suo file in Visual Studio solution projects

Visual Studio uses two type of file

  • .sln
  • .suo

These files help to store solution specific settings of visual studio .

The .suo file is a Visual Studio user settings file that stores data in a structured binary format and is used by VSPackage or solutions created using Visual Studio .

The .suo file contains the user preference configurations or per user settings.

MSDN description can be found in File Types and File Extensions in Visual Studio