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How to use ROT13 Encoder/Decoder

Type your text, and the tool shifts every letter 13 places through the alphabet — running the result through again restores the original.

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. A becomes N, B becomes O, etc.

Why is ROT13 used?

ROT13 is used to obscure text (like spoilers or puzzle answers) without true encryption. It's easily reversible—applying ROT13 twice returns the original text.

Does ROT13 work on numbers?

No, standard ROT13 only affects letters A-Z. Numbers and special characters remain unchanged.

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