ROT13/ROT5 Combo Tool

About this calculator

ROT13 shifts each letter 13 places through the alphabet (A→N, B→O, ...), which is its own inverse since the Latin alphabet has 26 letters — applying it twice returns the original text. ROT5 applies the same idea to digits, shifting each one 5 places through the 10-digit cycle (0-9), and is commonly paired with ROT13 so a combined transform obscures both letters and numbers in one pass (sometimes labeled ROT13.5 or ROT18).

It's a deliberately weak, non-cryptographic obfuscation used on forums and newsgroups to hide spoilers, puzzle answers, or joke punchlines from casual view, and it remains a staple exercise in programming tutorials for practicing modular arithmetic and string manipulation.