Cyphers & Encryption - Rot13 Cypher



This page allows you to encode and decode text that has been encrypted with the 'Rot 13' cypher. In modern times this does not provide the security of commercial systems like RSA or DES, but was commonly used in ancient times, and is still fun today.
Click on any of the links at the top of the page to reveal (or hide) more information about this calculator.


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At this point in time the calculators on this site are entirely dependent on JavaScript. Given enough time and money it is hoped to develop a version in the future which will be able to operate independently. Since JavaScript runs on your own computer, rather than on this server, it has been possible to set up this site much more quickly than if a server-side language was used, and it is possible to serve far more pages with the available bandwidth.
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The difference in position between each encrypted and un-encrypted character.
Short for 'Rotation'; referring to the fact that in the classical implementation of this cypher, the alphabet can be written in a circle, and larger numbers that would otherwise be beyond the end of the alphabet move round to the start of the alphabet.



  1. Type, or Copy-and-Paste the text to be encrypted / decrypted where indicated.
  2. Click the 'Encrypt/Decrypt' button below the input field.
  3. The encrypted text will be displayed below.
  4. To do further encryptions / decryptions simply change the text in the input field, and then click the 'Encrypt/Decrypt' button again.
Enter text to be encrypted here:
Encrypted Text:

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