A custom tracking system can provide functionality for operators of content sites to specify types of content delivery data to be tracked in a content delivery network. The custom tracking system can propagate operator tracking preferences to edge nodes in the content delivery network, such as delivery servers, which can track delivery data according to the preferences. The custom tracking system can use one or more tracking filters to reduce the storage burden of certain tracking requests while still providing relevant results. The custom tracking system can output results of the custom tracking for presentation to the content site operator.