Clustering images

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for clustering images. In one aspect a system includes one or more computers configured to, for each of a plurality of digital images, associate extrinsic image-related information with each individual image, the extrinsic image-related information including text information and co-click data for the individual image, assign images from the plurality of images to one or more of the clusters of images based on the extrinsic information associated with each of the plurality of images, receive in the search system a user query from a user device, identify by operation of the search system one or more clusters of images that match the query, and provide one or more cluster results, where each cluster result provides information about an identified cluster.