Context:Contemporary software development is a socio-technical activity requiring extensive collaboration among individuals with diverse expertise. Software testing is an integral part of software development that also depends on various expertise. GUI-based testing allows assessing a system’s GUI and its behavior through its graphical user interface. Collaborative practices in software development, like code reviews, not only improve software quality but also promote knowledge exchange within teams. Similar benefits could be extended to other areas of software engineering, such as GUI-based testing. However, collaborative practices for GUI-based testing necessitate a unique approach since general software development practices, perceivably, can not be directly transferred to software testing. Goal:This thesis contributes towards a tool-supported approach enabling collaborative GUI-based testing. Our distinct goals are (1) to identify processes and guidelines to enable collaboration on GUI-based testing artifacts and (2) to operationalize tool support to aid this collaboration. Method:We conducted a systematic literature review identifying code review guidelines for GUI-based testing. Further, we conducted a controlled experiment to assess the efficiency and potential usability issues of Augmented Testing. Results:We provided guidelines for reviewing GUI-based testing artifacts, which aid contributors and reviewers during code reviews. We further provide empirical evidence that Augmented Testing is not only an efficient approach to GUI-based testing but also usable for non-technical users, making it a promising subject for further research in collaborative GUI-based testing. Conclusion:Code review guidelines aid collaboration through discussions, and a suitable testing approach can serve as a platform to operationalize collaboration. Collaborative GUI-based testing has the potential to improve the efficiency and effectiveness of such testing.