Code Converter

Convert code from VB.NET to C# and vice versa using Roslyn - all free and open source:

Visual Studio extension
Online snippet converter
Command line dotnet tool install ICSharpCode.CodeConverter.codeconv --global (Requires VS2017+ installed)
Nuget library (this underpins all other free converters you'll find online)

See wiki for advice on getting the best results.

Visual Studio Extension

Adds context menu items to convert projects/files between VB.NET and C#. See the wiki documentation for advice / help using it.

Download from Visual Studio Marketplace (Use VS 2019+)

Flexible: Convert a small selection, or a whole solution in one go, in either direction.
Accurate: Full project context (through Roslyn) is used to get the most accurate conversion.
Safe: Conversion runs entirely locally - your code doesn't leave your machine.
Completely free and open source GitHub project.
Integrated: Uses the Output window to show conversion progress / summary.
Actively developed: User feedback helps us continuously strive for a more accurate conversion.

Contributing

Let us know what needs improving. If you want to get involved in writing the code yourself, even better! We've already had code contributions from several first time GitHub contributors, so don't be shy! See Contributing.md for more info.

Currently, the VB -> C# conversion quality is higher than the C# -> VB conversion quality. This is due to demand of people raising issues and supply of developers willing to fix them. But we're very happy to support developers who want to contribute to either conversion direction. Visual Basic will have support for some project types on initial versions of .NET 5, but won't be getting new features according to the .NET Team Blog.

Other ways to use the converter

Latest CI build (potentially less stable):
- See latest build
- Uninstall current version, click on a build and download/install the VSIX file at the bottom of the page
Integrating the NuGet library
- See CodeConversion.ConvertDocumentUnhandledAsync or CodeConversion.ConvertProjectUnhandled in the VSIX project.
- See ConverterController for a more web-focused API.

Building/running from source

Ensure you have .NET Core SDK 6.0
Open the solution in Visual Studio 2022+ (Community edition is sufficient)
To run the website, set CodeConverter.Web as the startup project

You will need Node (LTS) 16.* (node 17 introduces a breaking change causing ERR_OSSL_EVP_UNSUPPORTED)

To run the Visual Studio extension, set Vsix as the startup project
- A new instance of Visual Studio will open with the extension installed

History

A spiritual successor of the code conversion within SharpDevelop and later part of Refactoring Essentials, the code converter was separated out to avoid difficulties with different Visual Studio and Roslyn versions.