411 is an extension specific to files used by Sony Mavica digital cameras. 411 is a file in which thumbnails of images captured by the camera are saved. The 411 pixel resolution is 64x48. This solution allows you to quickly preview images without having to open their originals.

Mavic cameras saved images on removable disks (3.5-inch floppy disks or CDs with a diameter of 8 cm). Currently, the 411 format is rare and considered obsolete.