Apply ROT13, ROT13.5 or ROT47 – letter rotations used to hide spoilers and puzzle answers from casual reading. ROT13 is its own inverse, and it is not encryption.
Show calculation steps
Processed privately in your browser — nothing you paste is uploaded, logged or stored.
How to use the ROT13 Encoder and Decoder
- Paste the text you want to rotate.
- Choose the variant: ROT13 for letters, ROT13.5 to also rotate digits, or ROT47 to cover all printable ASCII.
- Click "Apply rotation". Running the same variant again returns the original text.
Frequently asked questions
Why is ROT13 its own inverse?
Because 13 is exactly half of 26. Rotating forward 13 places and then another 13 completes a full circle back to the starting letter, so one operation serves for both directions.
What is ROT13 actually for?
Hiding text from accidental reading rather than from an adversary – spoilers, puzzle answers, punchlines and offensive words in old Usenet posts. The reader must choose to decode it.
How do ROT13.5 and ROT47 differ?
ROT13.5 adds a rotation of five to the digits, so numbers are concealed too. ROT47 rotates all 94 printable ASCII characters by 47 places, covering punctuation as well – and like ROT13 it is its own inverse.
Is ROT13 encryption?
No. It has no key, so there is nothing to keep secret and nothing to break. Treating it as security would be a serious mistake.
Break or check a simple cipher
Plaintext from a classical cipher, or confirmation of which one was used.
- ROT13 Encoder and Decoder you are hereTry ROT13 first: it is its own inverse, so one pass tells you immediately.
- Caesar Cipher Encoder and DecoderTry every Caesar shift, since ROT13 is only the shift-13 case.
- Atbash CipherTry Atbash, which reverses the alphabet rather than rotating it.
- Vigenere Cipher Encoder and DecoderIf a single shift never works, the key is probably a word rather than a number.
