Providing customized autocomplete data

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing customized autocomplete suggestions. First profile data is obtained for a first user. Second profile data is obtained for second users that submitted search queries, where the second users are different from the first user. Based on the first profile data and the second profile data, similarity scores are determined. The similarity scores are each indicative of a degree of similarity between the first user and at least one of the second users. A proper subset of the search queries is selected based on the similarity scores, and an update for an autocomplete cache of a computing device associated with the first user is generated using the selected subset of search queries. The update is provided to the computing device associated with the first user.