Methods, systems, and apparatus, including computer programs encoded on computer storage media, for identifying answer boxes for presentation to a user. In general, one aspect of the subject matter described in this specification can be embodied in methods that include the actions of, while receiving an input entered in a search engine query input field by a first user, and before the first user has submitted the input as a search request, obtaining content for an answer box for the input and presenting the answer box to the first user. The answer box can be an answer box associated with a dominant query for the input, or can be an answer box identified from historical answer box data for the input.