What is a Caesar Cipher?
A Caesar Cipher is a simple substitution cipher that shifts each letter in a message by a fixed number of positions in the alphabet. It is one of the earliest and best-known encryption techniques, often used to introduce the basic idea of cryptography.
How to use this Caesar Cipher tool
- Enter or paste text into the input box.
- Choose a shift value and select Encode or Decode.
- Copy the transformed message from the output box.
Caesar Cipher examples
With a shift of 3, the word “HELLO” becomes “KHOOR”. To decode it, use the same shift in Decode mode.
Frequently asked questions
Is this Caesar Cipher decoder free?
Yes. DecodeNest tools are free to use and require no account.
Is my text uploaded?
No. The transformation runs locally in your browser.