Content search involves receiving a user-formulated search query via a user device. The search query is submitted to two or more search domains. The search domains represent separate data repositories accessible via the user device. Results objects are received from the two or more search domains in response to the search query. The results objects are ranked using different ranking criterion by the respective search domains from which the search results were received. A rank value for each of the results objects is determined based on a single ranking criterion. The results objects are ordered based at least in part on the rank values determined using the single ranking criterion and sent for display in a user interface of the user device.