ROT13 Encoder & Decoder
Obscure text using the classic ROT13 substitution cipher. Hide spoilers or puzzle answers with this simple, reversible encryption tool.
What is ROT13?
ROT13 ('rotate by 13 places') is a simple letter substitution cipher that replaces a letter with the 13th letter after it in the alphabet. Because the alphabet has 26 letters, applying ROT13 twice restores the original text. It is famously used on forums and newsgroups to hide spoilers, punchlines, and puzzle solutions.
Why Use Our ROT13 Encoder?
- Reversible: The same tool encodes and decodes the message.
- Forum Friendly: The standard way to hide spoilers online.
- Fast & Local: Encrypts text instantly in JavaScript.
- Leaves Symbols Intact: Only rotates A-Z, leaving numbers and punctuation alone.
How to Use the ROT13 Encoder
Paste your secret message or spoiler.
Click 'Apply ROT13'.
Share the obscured text with your friends.
Frequently Asked Questions
Absolutely not. ROT13 provides zero cryptographic security. It is meant only to hide text from a casual glance (like a spoiler).
All file processing is performed locally in your web browser. We do not upload, store, or view your data.