Find the name of the ASP.NET process

To debug a running ASP.NET app, the Visual Studio debugger must attach to the ASP.NET process by name.

To find out which process is running an ASP.NET app:

  1. With the app running, in Visual Studio, select Debug > Attach to Process.

  2. In the Attach to Process dialog, type the first letters of process names from the following list, or enter them into the search box. The one that is running is the one running the ASP.NET app. Attach to that process to debug the app.

    • w3wp.exe is IIS 6.0 and later.
    • aspnet_wp.exe is earlier versions of IIS.
    • iisexpress.exe is IISExpress.
    • dotnet.exe is ASP.NET Core.
    • inetinfo.exe is older ASP applications running in-process.


Visual Studio 2012 and earlier ASP.NET code can be on the file system and run on the test server WebDev.WebServer.exe or WebDev.WebServer40.exe. In this case, for local debugging, attach to WebDev.WebServer.exe or WebDev.WebServer40.exe instead of the ASP.NET process.

See also: