OBJ is a common file format used in 3D printing. Many CAD programs export 3D objects to OBJ formats. The OBJ file is accepted by most 3D printer software where it is prepared to 3D print.

The OBJ file was originally developed by Wavefront Technologies for use in its Advanced Visualizer animation package. It is an open file format and is now universally accepted and widely used by other 3D graphics application vendors.