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.
Why client-side?
Every byte you paste, type, or upload here is processed entirely inside your browser. Nothing is sent to a server, logged, or stored. That means it's safe to use this tool on production secrets, customer data, internal logs, and any input you would not paste into a hosted SaaS formatter.
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Frequently Asked Questions
- 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.