Pre-fetching resources by predicting user actions. Features of multiple users and of multiple client computer systems associated with the multiple users are obtained. From these features, multiple segments are generated, each including a proper subset of the multiple users. Users in the proper subset share a common feature. For a segment, resources that have at least a threshold level of likelihood of being requested by a user included in the segment are pre-fetched, i.e., obtained before the resources have been requested. A client computer system associated with the user in the included segment is identified, and the obtained resources are stored for providing to the user.