Languages and frameworks: C#
JetBrains Rider 2025.3 fully supports all C# versions up to C# 12.0. C# is the primary programming language JetBrains Rider is intended for, and therefore all JetBrains Rider features (excluding some features specific to other languages) are supported in C# .
Change language version
JetBrains Rider automatically detects and uses C# version specified in the project file *.csproj.
To change the version, open the project file in the editor and change the <LangVersion> attribute.
To set the C# version for all projects in your solution, specify it in a Directory.Build.props file in your solution directory as described here. Note that language versions defined in the .csproj files will override the versions specified in the Directory.Build.props file.
Depending on the current C# version JetBrains Rider adjusts its features. For example, code inspection detects places in your code, which could be simplified using new language features.
Information on JetBrains Rider features in C# is available in the following sections: