Testing becomes an important process in software development not only in terms of exposure but also in terms of performance, usability, safety, security, reusability. Also software testing is an essential activity to software quality assurance. Cloud testing is a method of software testing based on cloud computing that offers testing as a service To test the SaaS, NonSaaS, service application over clouds and clouds. To test the cloud-based software and applications, tools and techniques are needed to address concerns of the cloud infrastructure such as dynamic configuration. This paper provides a comprehensive assessment on cloud testing. It analyzed the questions raised by managers, tester and engineers, and it offers clear concepts, discusses the specific objectives, advantages, features and requirements, in cloud computing testing. Also, it offers a comparative view between cloud-based application testing and conventional software testing as well as the comparison between commercial testing tools and examines the advantages in testing cloud-based software applications.