ROT13 Encoder/Decoder
Encode or decode ROT13 text, live as you type.
ROT13 shifts each letter 13 places through the alphabet, wrapping around — since the alphabet has 26 letters, applying it twice returns the original text, so the same field both encodes and decodes. Only letters are shifted; numbers and punctuation are untouched. Converts live as you type, entirely in your browser.
What is ROT13 Encoder/Decoder?
ROT13 is a simple letter-substitution cipher that shifts each letter 13 places through the alphabet. Since the alphabet has 26 letters, applying ROT13 twice returns the original text — so the same tool both encodes and decodes, with no mode switch needed. It's been used online for decades to obscure spoilers, puzzle solutions, and forum joke answers from anyone skimming past — never for anything that needs real security. Conversion happens live as you type, entirely in your browser; nothing you enter is sent to a server.
FAQ
No — it's a trivial substitution cipher historically used to hide spoilers or puzzle answers from casual view, not to protect sensitive data. Anyone can reverse it instantly.
No, only letters A-Z and a-z are shifted; everything else passes through unchanged.
Because ROT13 is its own inverse — running the same 13-position shift a second time lands back on the original text, so a single field handles both directions.
Yes — an uppercase letter shifts to another uppercase letter and a lowercase letter to another lowercase letter, so the original casing pattern is preserved.