ROT13

How to Use

1. Enter text to convert
2. Click "ROT13 Convert" (encoding and decoding are the same operation)
3. Click "Copy" to copy the result

How It Works

ROT13 is a special case of the Caesar cipher with a fixed shift of 13. Since there are 26 letters in the English alphabet, shifting by 13 twice returns the original text.

Example: HELLO → URYYB → HELLO

Common Uses

• Hiding spoilers in forums
• Concealing puzzle or joke answers
• Simple text obfuscation
• Traditional Usenet newsgroup usage

常见问题

How is ROT13 related to the Caesar cipher?

ROT13 is the Caesar cipher with a shift of 13. Its special property is that encoding and decoding use the exact same operation, since 13 + 13 = 26.

Is ROT13 secure?

ROT13 provides no security whatsoever. It's not an encryption algorithm, just a simple text obfuscation method. Anyone can easily reverse ROT13 text.

Does ROT13 handle numbers?

Standard ROT13 only processes English letters (A-Z, a-z). Numbers, spaces, and punctuation remain unchanged. A variant called ROT5 handles digits (0-4↔5-9).