Swagger UI offers a web-based UI that provides information about the service, using the generated OpenAPI specification. Both Swashbuckle and NSwag include an embedded version of Swagger UI, so that it can be hosted in your ASP.NET Core app using a middleware registration call.
The web UI looks like this:
Swagger UI
Each public action method in your controllers can be tested from the UI. Select a method name to expand the section. Add any necessary parameters and select Try it out!
Example Swagger GET test
Note
The Swagger UI version used for the screenshots is version 2, while latest versions also exist.