This thesis deals with the topic of website optimization and user testing, with focus on the user experience. The main objective of this thesis is to design a software tool for on-line testing of the user experience of web applications, which currently does not exist on the Czech Internet. The first part deals with the user experience in theoretical aspect. It contains a comparison of experts' opinions on the issue and deals with the definition of basic concepts. The theoretical part contains an analysis of research techniques used in designing the user experience, which is an important output for the second part. Practical part of thesis includes at the beginning a research of the availability of tools to support analyzed research techniqu...