ROT13 / Caesar Cipher
Encode or decode text using classic substitution ciphers: ROT13, Caesar Cipher (custom shift), ROT47, and Atbash. All transformations run instantly in your browser.
Shift by 13 — apply twice to undo
Output will appear here
ROT13 is its own inverse — applying it twice returns the original text. Use the ⇄ button to decode.
Cipher Reference
| Cipher | Mechanism | Self-inverse? |
|---|---|---|
| ROT13 | Shift letters by 13 | Yes — apply twice to decode |
| Caesar | Shift letters by N (1–25) | Reverse shift to decode |
| ROT47 | Rotate printable ASCII !–~ by 47 | Yes |
| Atbash | A↔Z, B↔Y reversing the alphabet | Yes |