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ROT13 Cipher — Encode/Decode Instantly (Not Encryption)

ROT13 shifts each letter 13 places through the alphabet — the classic Usenet-era trick for hiding spoilers and puzzle answers from casual view. It provides zero real security: because the alphabet has 26 letters, applying ROT13 twice returns the original text, and anyone who recognises it can decode it in their head.

How to use ROT13 Cipher

  1. Paste your text.
  2. Read the ROT13 result instantly.
  3. Apply it again to the output to get back the original.

Frequently asked questions

Is ROT13 encryption?
No. It has no key and no real security — its only purpose is to obscure text from a casual glance, like hiding a spoiler, never to protect anything sensitive.
Why does applying ROT13 twice undo it?
The alphabet has 26 letters, and 13 is exactly half — shifting by 13 twice is a full 26-letter shift, which returns every letter to its original position.
What should I use instead for real security?
For anything that actually needs to stay confidential, use real encryption like AES rather than any classical substitution cipher.

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