Caesar Cipher Encoder

Enter text and a shift number to encode or decode with the Caesar cipher.

Shift (1–25)

Encode Decode

Enter text on the left and click Apply Cipher to begin.

How to use

What shift does the Caesar cipher traditionally use?

Julius Caesar reportedly used a shift of 3, but the cipher works with any shift from 1 to 25.

How do I decode a Caesar cipher if I do not know the shift?

Try all 25 shifts - this is called brute force. The correct shift produces readable text. ROT13 is simply shift 13.

Does the Caesar cipher work with lowercase and uppercase?

Yes. This tool preserves the original case while shifting letters within their respective case range.

Is the Caesar cipher used in real cryptography?

No. It is far too simple to provide security. It is used only for education and puzzles.