ROT13 Cipher

ROT13 rotates every letter of the English alphabet by 13 positions, wrapping around at the end. Because the alphabet has 26 letters, applying ROT13 twice returns the original text, so the same operation both encodes and decodes.

1. Paste your text into the Input area. 2. Click the Convert button to apply ROT13. 3. Review the result in the Result card and use Copy to copy it. To decode ROT13 text, paste it into the Input and click Convert again.

Only ASCII letters (a-z, A-Z) are rotated; digits, punctuation, whitespace, and non-letter characters are passed through unchanged. Letter case is preserved: uppercase letters map to uppercase and lowercase to lowercase. The rotation is by exactly 13 positions, so A becomes N, B becomes O, N becomes A, and so on, which makes the operation its own inverse.