The VBC command, short for Visual Basic Compiler, is a command-line tool used to compile Visual Basic .NET programs from source code into executable files (.exe) or dynamic-link libraries (.dll). The primary purpose of VBC is to facilitate the development of VB.NET applications directly from the command line or in scripts, making it especially useful in automated build environments or for developers who prefer command-line tools over integrated development environments (IDEs).


The basic syntax of the VBC command is as follows:

vbc [options] [sourcefile.vb ...]
  • [options]: Represents compiler options such as output type, target platform, and references.
  • [sourcefile.vb …]: One or more Visual Basic source files to be compiled. Multiple files can be separated by spaces.


Below are some commonly used options for the VBC command:

  • /out:: Specifies the output file name.
  • /target: Specifies the format of the output, ex. winexe, exe, library, or module.
  • /reference: Alias /r. Specifies an assembly reference.
  • /debug: Includes debug information.
  • /nowarn: Suppresses specified warnings.
  • /optionexplicit: Enforces explicit declaration of variables.

For a full list of options, consult the official Microsoft documentation.


  • Compiling a single file into an executable:
    vbc /out:MyProgram.exe MyProgram.vb
  • Compiling multiple files into a DLL:
    vbc /target:library /out:MyLibrary.dll File1.vb File2.vb
  • Adding references and debug information:
    vbc /reference:system.dll /debug /out:MyApp.exe MyApp.vb

Common Issues

  • Missing References: If your code refers to external libraries that are not referenced, you’ll encounter errors. Use the /reference option to include all necessary assemblies.
  • Syntax errors in source files: Ensure that all VB.NET source files are syntactically correct.
  • Output file not created: Check permissions of the output directory and ensure it’s not write-protected.


VBC can be integrated into automated build scripts. You can use CMD commands like echo and del to manage output messages and clean up old executable files before a new build.

Example in a batch script to compile and run a VB.NET program:

echo Cleaning up...
del MyApp.exe
echo Building...
vbc /out:MyApp.exe MyApp.vb
echo Running...
  • MSBuild: Builds .NET and Visual Studio projects from command line.
  • csc: Command-line compiler for C# source files.

For more information, please refer to the official documentation on Microsoft Docs.