If we need a Web Service and don’t need SOAP, then ASP.Net Web API is best choice. It is Used to build simple, non-SOAP-based HTTP Services on top of existing WCF message pipeline. It doesn't have tedious and extensive configuration like WCF REST service. Simple service creation with Web API. With WCF REST Services, service creation is difficult. It is only based on HTTP and easy to define, expose and consume in a REST-ful way. It is light weight architecture and good for devices which have limited bandwidth like smart phones. It is open source.