Encode Text with Caesar Cipher Online
Apply the classic Caesar cipher substitution to encode messages. Shift each letter by a chosen number of positions in the alphabet - includes ROT13 as the default.
ROT13 / Caesar Cipher
Encode, decode, and crack Caesar cipher and ROT13 with brute force and frequency analysis
Alphabet Mapping
| Plain | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
| Cipher | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M |
How It Works
- Caesar Cipher: Each letter is shifted by a fixed number of positions in the alphabet. A shift of 3 turns A into D, B into E, etc.
- ROT13: A special case of Caesar cipher with shift 13. Since 13 is half of 26, encoding and decoding are the same operation.
- ROT5: Shifts digits 0-9 by 5 positions. 0 becomes 5, 1 becomes 6, etc.
- ROT47: Shifts all printable ASCII characters (33-126) by 47 positions. Covers letters, numbers, and symbols.
- Brute Force: Try all 25 possible shifts to decode an unknown Caesar cipher. Look for readable English in the results.
Quick Start
- 1Enter the text you want to encode
- 2Set the shift value (default 13 for ROT13)
- 3The encoded text appears instantly
- 4Copy the encrypted message
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Looking for FAQs and advanced options? Visit the full ROT13 / Caesar Cipher page →