Family name Janzi (Janzi 
) , in all the world, is a very rare cognomen. The last name Janzi is habitual in Switzerland, where it is a rare surname, Nicaragua, where it is a very rare surname, and Mexico, where it is an extremely rare surname. Measured by absolute frequency, it most frequently occurs in Switzerland, Mexico, and Thailand. Also, Janzi is the forename as well as the last name.