Caesar Cipher
Encrypt and decrypt text with the Caesar shift cipher or ROT13, and crack unknown shifts by brute force.
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How to use the Caesar Cipher
- 1
Choose Encode or Decode and set the shift, or press ROT13.
- 2
Type or paste your text.
- 3
Copy the result, or use the brute-force list to find an unknown shift.
Frequently asked questions
What is ROT13?
A Caesar cipher with a shift of 13. Because the alphabet has 26 letters, applying ROT13 twice gives back the original text.
How does the brute-force list find the right shift?
It tries all 25 shifts and compares each result's letter frequencies with English. The closest match is highlighted.
Is the Caesar cipher secure?
No. It is easy to break and should only be used for puzzles, games and learning.