The instant worldwide audience of a Web site make its quality and reliability crucial factors in its success. Correspondingly, the nature of the WWW and Web sites pose unique software testing challenges. Webmasters, WWW applications developers, and WebSite quality assurance managers need tools and methods that meet their specific needs. Mechanized testing via special purpose WWW testing software offers the potential to meet these challenges. Our technical approach, based on existing WWW browsers, offers a clear solution to most of the technical needs for assuring Web site quality.