Methods, systems, and apparatus, including computer program products, for correcting spelling in text. A text input is received for translation. One or more suspect words in the text input are identified. For each suspect word, one or more candidate words are identified. A score for the text input and scores for each of one or more candidate inputs are determined, where each candidate input is the text input with one or more of the suspect words each replaced by a respective candidate word. If any, a candidate input whose score is highest among the scores for the candidate inputs and is greater than the text input score by at least a threshold is selected. Otherwise, the text input is selected. A translation of a selected candidate input or the selected text input is provided as the translation of the text input.