Developer: How to find bitness (x86 or x64) of a given application?

I hear this query a lot how to find a bitness of a given application. Recently one of my customer followed by blog post and asked is there any alternate way exists to find out the bitness of installed Outlook in your environment.  He is an app developer, so he installed Microsoft Visual Studio at his environment. So I suggested him to make use of dumpbin.exe (Microsoft COFF Binary File Dumper).

Bitness of app

Using the above we found the Outlook installed is x64 bit.

In addition, we tested with against MFCMAPI utility as well using dumpbin and here is the result - x86 bit:

MFCMAPI & dumpbin


  • The Microsoft COFF Binary File Dumper (DUMPBIN.EXE) displays information about Common Object File Format (COFF) binary files. You can use DUMPBIN to examine COFF object files, standard libraries of COFF objects, executable files, and dynamic-link libraries (DLLs)
  • You can start this tool only from the Visual Studio command prompt.
  • You cannot start it from a system command prompt or from File Explorer.

Hope this helps.