Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for receiving a query initial input from a user, in response to receiving the query initial input, determining a set of personalized query suggestions based on the query initial input, the set of personalized query suggestions including one or more content-based query suggestions that reflect at least one of user data associated with the user within one or more computer-implemented services and use of the one or more computer-implemented services by the user, and transmitting instructions to display the set of personalized query suggestions to the user.