Caesar Cipher Tool

Caesar Cipher Explained

The Caesar cipher is one of the oldest and simplest forms of cryptography. It is a type of substitution cipher where each letter in the plaintext is shifted a certain number of places down or up the alphabet. This number is known as the **key**.

Our online tool simplifies this process, allowing you to encrypt or decrypt any message instantly. Just enter your text, set a key between 1 and 25, and click the appropriate button. The tool works with both uppercase and lowercase letters and ignores numbers and symbols.

How to Use This Tool

Simply enter your text in the left box. Choose your cipher key from 1 to 25. Click **Encrypt** to shift the letters forward, or **Decrypt** to shift them backward. The result will appear in the right box. You can then copy the output to your clipboard or download it as a text file.