Caesar Cipher Tool

Caesar Cipher Tool – Encode & Decode Text Online

The Caesar cipher is one of the earliest and simplest methods of encryption in history. It works by shifting each letter in the alphabet by a fixed number of positions, also called the key. For example, with a shift of 3, A becomes D, B becomes E, and so on. This makes it a fun and easy way to understand the basics of classic cryptography.

Our free Caesar Cipher Tool lets you quickly encrypt and decrypt text online. Just type your message, choose a key value between 1 and 25, and instantly see the encoded or decoded result. The tool works with both uppercase and lowercase letters while ignoring numbers, spaces, and special characters.

Whether you’re learning about cryptography, exploring historical ciphers, or just want to send a secret message to friends, this tool makes the Caesar cipher simple and interactive. Try it out now and discover how ancient encryption worked!

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.