This script will encode or decode ROT13 text typed or pasted in the left field below. ROT13 is a simplistic form of encryption. To be technically accurate, it is not really encryption, but encoding. It is most often used to prevent something from being read by accident. For example something that might give away the ending of a film, or a crude joke that might cause offense. Most electronic mail readers, and USENET news readers can decode ROT13.