Techniques for providing dynamic categories are disclosed. In some embodiments, a system for providing dynamic categories includes receiving user context data, and dynamically determining a plurality of categories for the user based on the user context data, in which the plurality of categories are for categorizing content on a web site. For example, the user context data can be based on monitored user behavior on a web site, and one or more of the plurality of categories can include a synthesized category on the web site that is dynamically generated based on the monitored user behavior on the web site.