.NET Upgrade Assistant

.NET Upgrade Assistant is a free, open-source Microsoft tool, distributed as a Visual Studio component and a standalone CLI, that scans a .NET Framework, .NET Core, or older .NET project for incompatibilities and walks a developer through upgrading project files, package references, and configuration to a current .NET version. Microsoft introduced it in 2021 under the dotnet GitHub organization, and it supports C# and Visual Basic projects including ASP.NET, WPF, WinForms, and Xamarin Forms. As of 2026, Microsoft has officially deprecated the tool in favor of the GitHub Copilot app modernization chat agent bundled with current Visual Studio releases; the legacy CLI still runs, but Microsoft is directing new upgrade work to the AI-based successor rather than continuing active development of Upgrade Assistant itself.