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ROT13 Encoder and Decoder

Rotates every letter 13 places in the alphabet. Running it twice gives back the original text.

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What is ROT13?

ROT13 is a very simple letter substitution cipher. Every letter is replaced by the letter 13 places further along the alphabet, so A becomes N and N becomes A.

It is not real encryption. It is used to hide spoilers and puzzle answers so that they are not read by accident.

What this tool does

Rotates every letter of your text by 13 places and leaves numbers, spaces and symbols alone. Because the alphabet has 26 letters, applying ROT13 twice gives back the original text.

How to use it

  1. Type or paste your text.
  2. Read the ROT13 result.
  3. To decode, paste the result back in.

Did you know?

  • ROT13 was popular on early internet forums for hiding joke punchlines and spoilers.
  • It is a special case of the Caesar cipher, named after Julius Caesar, who is said to have used a shift of three.

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