Websites and software development has become one of the most demanded professions in this era of information and technology. Large number of skilled developers is available who provide their services throughout the world. One of the crucial parts of development is testing the program whether it is working perfectly or not. To simplify this task, various testing tools are available on internet that helps the developer to analyze if there is any error or bug left in program that is stopping it from working fluently. With the help of these coding playgrounds for developers, one can easily identify the problems and fix them with suitable solution.