We have seen that now web is really becoming cross plate form and you can see your services or API can be exposed to any client. Till now one of big challenges is to choose platform for this kind of service. There are so many options available like web services, WCF services,Generic Handlers, directly writing responses on aspx page etc. There are plenty of options available and each one has their own pros and cons. But now we have one simpler answer for that is ASP.NET Web API. What is Web API? ASP.NET Web API is a framework for building web API on the top of .NET framework. It’s a framework for building and consuming web services that can be use at broad range of clients like browsers,tablets phones etc. You can expose JSON or XML whatever you want to use.