Why is ROT13 special?

Applying ROT13 twice returns the original text — it's self-inverse — so the same tool both encodes and decodes.

ROT13 / Caesar Cipher

Apply a Caesar shift to text. ROT13 is the famous self-inverse version. Useful for puzzles, spoilers, light obfuscation.

Shift

Input Result

Load file

Unix (LF) Dos (CRLF)

How to use ROT13 / Caesar Cipher

Paste your text.
Set the shift value (or click ROT13 for the classic 13).
Copy the result.

What is ROT13 / Caesar Cipher?

The Caesar cipher is one of the oldest known ciphers, dating to Julius Caesar's correspondence. It shifts each letter forward or backward by a fixed amount in the alphabet. ROT13 — a shift of 13 — is self-inverse and widely used to hide minor spoilers in online discussions.

This is not real encryption. Don't use it for anything sensitive.

FAQ

Why is ROT13 special?: Applying ROT13 twice returns the original text — it's self-inverse — so the same tool both encodes and decodes.

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