The introduction of mobile devices with smaller screens motivates the need for web pages that work correctly across many different devices—referred to as responsive web design. Mobile access is a key feature for companies: both to reach new customers, and also to provide an enhanced service to existing customers. Testing the correct appearance of a responsive web page on different devices is not a trivial task because there are no standard rules for responsiveness, and the layout may need to be significantly rearranged in order to fit on smaller screens. This dissertation describes an investigation into the automated test case generation for responsive web pages. The aim of the project is to develop a novel approach to test responsive web pages for the consistency of their appearance. This thesis develops the idea of consistent web pages which are not identical but provide essentially the same interface to the user. The goal of this project is to develop approach on how to do automated test case generation of the appearance of responsive web page and to evaluate this approach by building a test tool that automate the testing of consistency of responsive web pages against the master copy of the page. Several rules were implemented for comparing web pages displayed on different screens. The results show that the approach taken is an effective way of automating testing for consistency. This dissertation also identifies a number of unanswered research issues to be addressed by future work.