ROT13 Encoder & Decoder
Apply the ROT13 letter cipher.
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Encode and decode with ROT13
ROT13 is a simple letter substitution that rotates each letter thirteen places through the alphabet. Because the alphabet has twenty-six letters, applying it twice returns the original, so one tool both encodes and decodes. Type your text to scramble it, or paste ROT13 text to reveal it. It is widely used to hide spoilers, puzzle answers and punchlines in plain sight rather than for real security. Numbers and symbols pass through unchanged, and it all runs locally.
Why it is reversible
Shifting by thirteen and then thirteen again moves a letter a full twenty-six places, landing back where it started.
Frequently asked questions
Is ROT13 secure?
No. It only hides text from a casual glance, such as spoilers or answers. Anyone can reverse it instantly, so never use it to protect real secrets.
Why does encoding equal decoding?
Thirteen is exactly half of twenty-six, so applying the shift twice returns each letter to its starting position.