The number of devices connecting to the Internet is increasing day by day. Firstly, people connected the Internet using their personal computers with the purpose of gathering information, then Internet became more accessible with the increased popularity of portable computers and mobile phones. Today, smart home management systems and many other devices have become interconnected over the Internet. As the result of these devices being used in every aspect of people's lives, they can accomplish many of daily tasks, easier than ever. Internet connected devices are generally called, 'Internet of Things (IOT)". As IOT become more and more popular, web application programming interfaces (WebAPIs) are now more important than ever. Today, all these devices, systems and modules are mostly integrated over WebAPIs, so performance and scalability features of the WebAPIs are getting very important. WebAPIs can be developed with many different programming languages using different frameworks and environments. In this paper, sample prototype RestAPIs which is a special WebAPI class will be developed using different programming languages and environments and the performances of these RestAPIs will be compared against each other with load tests and stress tests.