Organizations have adopted modern structure of involving Cloud services and Mobile, and the result we catch sight is a mammoth system that supports these simple-looking applications. API Testing is a software that authenticates Application Programming Interfaces (APIs). This grounds to check the functionality, reliability, performance and security of the programming interfaces. In API Testing, instead of using standard user inputs(keyboard) and outputs, software is used to send calls to the API and jots down the system’s response. The software of API testing services has been architectured such that it brings to bear on the business logic.