SpecFlow
SpecFlow is a Behavior-Driven Development framework for .NET that runs Gherkin-written scenarios, mapping each step to C# step-definition code — the .NET ecosystem's equivalent to Cucumber, integrating directly with Visual Studio and the standard .NET test runners.
Like Cucumber, SpecFlow itself only handles parsing Gherkin and executing matching step definitions — actual browser or API automation underneath is typically handled by Selenium, Playwright for .NET, or a REST client, with SpecFlow providing the BDD structure and readable specification layer on top.
Its tight Visual Studio integration — feature files with syntax highlighting, one-click "generate step definitions" for unmatched steps, inline test results — is a major reason it became the default BDD choice for .NET teams specifically, rather than reaching for a more general, language-agnostic tool.
