keygen generates working, high-quality 3D-printable models of keys based on given parameters. To generate a key, select your key type and shapes. Then, follow the instructions on how to properly enter the bitting. Click 'Download STL' to save your key in a format suitable for 3D printing. This site is simply a web interface to keygen, a light wrapper around OpenSCAD. You can download and use this tool offline if you so desire.