Mole Visual Studio Debugger Visualizer


Mole is a debugger visualizer that runs in Visual Studio while you are debugging .NET applications. Mole makes debugging easier because it provides a comprehensive view into all of your application’s visual and data objects.

Mole enables developers to view, edit, search, compare, and drill into object properties and fields.

Mole is only supported on the Professional and Enterprise versions of Visual Studio 2015.

I strongly encourage you to view the below training videos, especially “How to Open Mole”.  If you have never used a Visualizer before or don’t know how Visual Studio launches them, you’ll be frustrated.  Please watch the videos and have a happy debugging experience with Mole.

Even the early releases (2007-2008) of Mole had debugger visualizer features that were ground breaking and ahead of their time.

Enjoy Mole and happy debugging.


Back in December 2007 Rock Star Programmer Josh Smith wrote a debugger visualizer called Woodstock. There were other developers investigating the visualizer space and posting visualizers on Code Project.  This sparked my interest so I jumped in and wrote the first version of Mole.  Josh and I then teamed up with genius, low level .NET superstar, Andrew Smith.  The three of us worked and released the final public release of Mole.

When Visual Studio 2010 was released Nathan Dunlap joined the Team Mole, we started Molosoft LLC and wrote a commercial version of Mole.  After three years we closed Molosoft for financial reasons and Mole was taken off the market.

May 2016, Mole was released on the Visual Studio Gallery free of charge.  This version of Mole supports Visual Studio 2015.  I will release new versions of Mole, including feature enhancements any bug fixes with each new version of Visual Studio.

It is important to know that Mole was a collaborative effort and a lot of hard work by Team Mole: Josh Smith, Andrew Smith, Nathan Dunlap, and me Karl Shifflett.  Without this, the high-octane, polished version of Mole would have never been released.

ASP.NET Developers Please Read This

When using Mole with ASP.NET projects that utilize IIS as the web server, as opposed to the Visual Studio’s built in web server, you MUST give the account that the web site is running under, Read and Read & Execute permissions to the \Visualizers directory.

If you do not do this, you will get an exception when attempting to load the visualizer in a debugging session. You would get this exception for any visualizer and not just Mole. This is because the ASPNET account has very few permissions on your computer. Adding these permissions prevents this exception.


Mole is installed from the Visual Studio Gallery.


To make a donation click here.

Training Videos

Please watch these four short videos to get the most from Mole.





Launching Mole

Mole, like all Visual Studio Debugger Visualizers, is launched from a Data Tip, while at a breakpoint.

The below image show the Data Tip after hovering over the sender argument.

To open any available Visualizer, click on the magnifying glass down arrow, and a list of available visualizers will be displayed.

Unfortunately, in Visual Studio 2015, Microsoft has decided to remove the feature from the visualizers list that remember which visualizer was last used. Not sure why they hijacked the default visualizer the way they did. Makes no sense.


Data Tip Tool Small

If you find the Data Tip is too small, there is a workaround for this.  Just change its font size using the Visual Studio Options dialog.