What it does
xUnit.net is a test framework for .NET applications, with support for C#, F#, and Visual Basic. Its project templates and assertions work with the .NET SDK command line, while the framework also integrates with Visual Studio, Visual Studio Code, Rider, and compatible test platforms. Version 3 targets .NET 8 or later and .NET Framework 4.7.2 or later. Developers provide the code under test and write the expected behavior as unit tests; xUnit.net discovers and reports the results through the chosen runner.
Generate a test project and make an assertion
Install a .NET SDK, create a test directory, and follow the official guide's dotnet new xunit3 command to generate an xUnit.net v3 project. The template includes a sample test. A useful next change is to replace the placeholder with a [Fact] method that calls a function in the application and checks its result with an assertion such as Assert.Equal. The guide demonstrates running the project with dotnet run; this is documentation, not a command executed for this listing.
The framework handles discovery and test output, while the developer supplies the behavior to verify and chooses the runner that fits the repository. xUnit.net supports the .NET SDK command line as well as IDE and test-platform integrations. The official v3 guide covers C#, F#, and Visual Basic templates.
Check the target framework first
The project site lists .NET 8 or later and .NET Framework 4.7.2 or later for v3. The guide notes that .NET Framework is officially supported only on Windows; for cross-platform work, use a supported modern .NET target and verify the chosen runner. The project is open source under Apache 2.0, but it is a unit-testing library, not a hosted browser, device, or performance-testing service.
Strengths
- The v3 templates provide a quick way to create test projects in C#, F#, or Visual Basic.
- Tests run through the .NET SDK and integrate with common IDEs and compatible test platforms.
- The framework's test cases and assertions live alongside application code, making unit behavior repeatable in a developer workflow.
Watch out for
- Version 3 requires .NET 8 or later or .NET Framework 4.7.2 or later; the official guide limits .NET Framework support to Windows.
Best for
- Developers writing unit tests for C#, F#, or Visual Basic code
- Repositories that want .NET SDK test templates and command-line execution
- Teams integrating unit tests with Visual Studio, VS Code, Rider, VSTest, or Microsoft Testing Platform
Sources
- Home | xUnit.net (Oct 26, 2026)
- Getting Started with xUnit.net v3 (Oct 26, 2026)
- xUnit.net source repository (Oct 26, 2026)
- xUnit.net source license (Oct 26, 2026)