Abstract: Methods for configuring website categorization software, categorizing websites and a method and system for controlling access to websites. A number of websites are selected, all of which relate to a single predetermined category of subject matter. In order to create a category profile, a website is selected from the set (3), the website markup language is read (5), page content information extracted (7) and then analyzed (9). The system may then check whether it has analyzed a sufficient number of websites to allow for a reliable categorization of subsequent websites (13). Individual websites are categorized by extracting their page content information (45) and categorizing (51) on the basis of the degree of similarity between the information and the category profile (55). To control access, the system compares a website identifier with the database of categorized identifiers.