Caesar Cipher

Encrypt/decrypt using the Caesar cipher.

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Features

Adjustable Shift

Choose any shift value from 1 to 25 to encrypt your text.

Two-Way Cipher

Encrypt plain text to cipher text, or decrypt cipher text back to plain text.

Live Encryption/Decryption

The tool updates in real-time as you type or change the shift value.

About Caesar Cipher

The Caesar cipher is one of the simplest and most widely known encryption techniques. It's a substitution cipher where each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. This tool allows you to both encrypt and decrypt messages using this classic method.

How to Use Caesar Cipher

  • 1
    Set Shift Value

    Use the slider to select a shift value (1-25). This determines how many places each letter is shifted.

  • 2
    To Encrypt

    Type your message in the "Plain Text" box. The encrypted text will appear instantly on the right.

  • 3
    To Decrypt

    Type the encrypted message in the "Cipher Text" box. The decrypted text will appear on the left.

  • 4
    Copy

    Click the copy button to save the result.

Frequently Asked Questions

A Caesar Cipher is a simple substitution technique where each letter in the text is shifted a certain number of places down the alphabet. For example, with a shift of 1, A would be replaced by B, B would become C, and so on.
The shift value (or key) determines how many positions each letter moves. If you use a shift of 3 (classic Caesar), 'A' becomes 'D'. If you shift by 26, the text wraps around and remains unchanged.
No, it is very easy to crack. Since there are only 25 possible shifts, someone can easily try all of them (brute force) to reveal the original message. It should not be used for secure communication.
ROT13 is actually a specific type of Caesar Cipher with a fixed shift of 13. While a Caesar Cipher allows you to choose any shift from 1 to 25, ROT13 always shifts by exactly 13 places.
It is named after Julius Caesar, who used it to communicate with his generals. He famously used a shift of 3 to protect his military messages.
If you shift by 0 or 26 (the number of letters in the alphabet), the text remains exactly the same, as you have rotated full circle back to the start.