About the ROT13 Encoder and Decoder
ROT13 (“rotate by 13 places”) replaces each letter with the letter 13 positions later in the alphabet, so A becomes N and N becomes A. Because the alphabet has 26 letters, applying ROT13 twice returns the original text, which means the same button both encodes and decodes.
It is a simple form of the Caesar cipher and gives no real security. It is traditionally used online to hide spoilers, punchlines and puzzle answers so that readers do not see them by accident. Only the English letters A–Z are changed. Numbers, punctuation and other characters are left alone.
How to use it
- Paste text to encode or decode.
- Click Apply ROT13.
- Copy the result. Apply it again to reverse it.
Example
The butler did it! (Chapter 12)
Gur ohgyre qvq vg! (Puncgre 12)
When to use it
- Hiding spoilers in forums and reviews.
- Concealing quiz and puzzle answers.
- Teaching the basics of ciphers.
- Lightly obscuring text from casual reading.
Frequently asked questions
Is ROT13 secure?
No. It is trivial to reverse and should never be used to protect sensitive information.
How do I decode ROT13?
Apply ROT13 again. Encoding and decoding are the same operation.
Are numbers changed?
No. Only the letters A–Z and a–z are shifted.
Is the text I enter kept private?
Yes. The ROT13 Encoder and Decoder runs entirely in your web browser, so your text is never uploaded to or stored on our servers. Like most free websites, TextForge shows ads from Google, which may use cookies. See our Privacy Policy for details.