ROT13 Encoder/Decoder - ROT5/13/18/47

ROT13 is a special case of the Caesar cipher with a shift of 13 positions. Since the English alphabet has 26 letters, ROT13 encryption and decryption are identical operations — applying ROT13 twice returns the original text. Unlike the general Caesar cipher which can use any shift from 1 to 25, ROT13 uses a fixed 13-position shift.

ROT5 shifts digits 0-9 by 5 positions; ROT13 shifts letters A-Z/a-z by 13 positions; ROT18 is a combination of ROT5+ROT13 that handles both digits and letters; ROT47 shifts all printable ASCII characters from 33 to 126 by 47 positions, offering the widest coverage.

ROT13 is NOT a secure encryption method. It's a simple text obfuscation tool with no key — anyone can read the output directly. It's commonly used for hiding spoilers in forums, puzzle games, or as a programming exercise. Never use it to protect sensitive information.

Absolutely not. This tool runs entirely in your browser. Your text is processed in memory and never sent to any server. It works perfectly even without an internet connection after the page loads.

ROT5/13/18 only process English letters and digits — non-English characters like Chinese, Japanese, or accented letters pass through unchanged. ROT47 shifts all printable ASCII characters and also leaves non-ASCII characters untouched.