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ROT13 Cipher
Processed Locally
Encode and decode text using ROT13 cipher. A simple letter substitution that rotates alphabet by 13 positions
Frequently Asked Questions
ROT13 is a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. It's a special case of the Caesar cipher. Since there are 26 letters in the English alphabet, applying ROT13 twice returns the original text (it's its own inverse).
No! ROT13 is NOT a secure encryption method. It's trivially easy to decode and should never be used for protecting sensitive data. It's mainly used for hiding spoilers, puzzle solutions, or jokes - not for real security.
Because ROT13 shifts by half the alphabet (13 out of 26 letters), applying it twice shifts by 26 positions, which brings you back to the original letter. This property makes ROT13 self-inverse: the same function both encodes and decodes.
ROT13 only affects letters (A-Z, a-z). Numbers, punctuation, spaces, and special characters remain unchanged. The case (uppercase/lowercase) is preserved.