ROT13 Encoder / Decoder
Apply the ROT13 substitution cipher to your text. Encoding and decoding use the same operation.
About the ROT13 Encoder/Decoder
Apply the ROT13 substitution cipher to your text. Encode and decode ROT13 with one click.
Private by design
Everything you type here is processed inside your browser. Nothing is sent to a server, logged or stored, so it is safe to use with real numbers, drafts and anything you would not paste into a hosted tool.
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Questions people ask
What is ROT13?
ROT13 is a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. It's its own inverse — applying ROT13 twice returns the original text.
Is ROT13 secure?
No. ROT13 is not encryption. It's a trivial cipher mainly used to obscure spoilers, puzzle answers, and similar casual use cases.
Does ROT13 affect numbers and symbols?
No. ROT13 only transforms letters (A-Z, a-z). Numbers, spaces, punctuation, and symbols remain unchanged.