Web applications have gained increased popularity in the past decade due to the ubiquity of the web browser across platforms. With the rapid evolution of web technologies, the complexity of web applications has also grown, making maintenance tasks harder. In particular, maintaining cross-browser compliance is a challenging task for web developers, as they must test their application on a variety of browsers and platforms. Existing tools provide some support for this kind of test, but developers are still required to identify and fix cross-browser issues mainly through manual inspection. Our WEBDIFF tool addresses the limitations of existing tools by (1) automatically comparing the structural and visual characteristics of web pages when they are rendered in different browsers, and (2) reporting potential differences to developers. When used on nine real web pages, WEBDIFF automatically identified 121 issues, out of which 100 were actual problems. In this demo, we will present WEBDIFF, its underlying technology, and several examples of its use on real applications.