Web application testing is becoming increasingly important with Web applications becoming more prevalent. Many proposed test tools have been evaluated through experiments using programs that have been seeded with bugs. However, such bugs are seeded manually or seeded using past bug information, and as a result they are not seeded exhaustively. In this paper, we focus on mutation testing where bugs are systematically seeded. We propose a framework for evaluating test suites that have been generated for Web applications. We conducted an experiment where we applied the implemented framework to a sample application. We discuss the experimental results.