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ROT13 and Caesar Cipher Tool

Encode or decode ROT13, ROT47 and Caesar ciphers.

  • Free
  • No sign-up
  • Nothing is sent or stored
Cipher

ROT13 is its own inverse — run it again to decode.

0 characters
These ciphers hide spoilers and puzzle answers — they are not secure encryption.

The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved.

How to use the ROT13 & Caesar Cipher

  1. Choose ROT13, Caesar shift or ROT47.
  2. For Caesar, set the shift and direction.
  3. Type your text and copy the result.

What does this tool do?

A Caesar cipher shifts each letter a fixed number of places in the alphabet. ROT13 shifts by 13, so applying it twice gets you back to the original — which is why it's popular for hiding spoilers and puzzle answers.

ROT47 extends the idea to digits and punctuation. None of these ciphers is secure; use proper encryption for anything private.

Why use it?

  • Three classic ciphers.
  • Any Caesar shift.
  • Instant results.

Privacy

The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved. There's no account to create and nothing to install.

Last reviewed by the M2Toolkit team.

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