The Java sparrow is about 15 to 17 cm (5.9 to 6.7 in) in length from the beak to its tip of tail feathers. Although only about the size of a house sparrow, it may be the largest species in the estrildid family. The adult is unmistakable, with its grey upperparts and breast, pink belly, white-cheeked black head, red eye-ring, pink feet and thick red bill.