One of the current core requirements of web applications is the continuity of the service, because loss in availability can lead to severe economic losses. This is the main reason behind the growing interest in web application testing that offers to researchers several challenges, due to the peculiar nature of these applications. Several classical testing techniques have been extended to deal with web testing. In this paper we propose to extend to web application testing a recent search-based approach that optimizes the generation of the whole test suite. This approach has several advantages over common approaches that optimize the generation of a single test case at a time. We show the technological challenges we have had to face, the architecture of the tool WETT we have developed, and some preliminary results of the experiments.