Caesar Cipher Encoder & Decoder
Shift letters by any amount to encode or decode Caesar ciphers, with a full brute-force view.
Frequently Asked Questions
What is the Caesar cipher?
A substitution cipher where each letter is shifted a fixed number of places in the alphabet. Julius Caesar reportedly used a shift of 3 to protect military messages.
What is ROT13?
ROT13 is the Caesar cipher with a shift of 13. Because 13 is half of 26, encoding twice returns the original text, so the same operation encodes and decodes.
How does the brute-force view help?
If you do not know the shift, the table shows all 25 possible decodings at once. The correct shift produces readable English, which stands out immediately.
Is the Caesar cipher secure?
No. With only 25 possible keys it is trivially broken, so use it for puzzles and fun, never for real secrets. Use modern encryption for anything sensitive.
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