Caesar Cipher Encrypt/Decrypt
Classic Caesar cipher (shift) encrypt/decrypt tool with custom shift and one-click copy
Input text
Shift
Range 1-25
Shift:
3
Only English letters (A-Z / a-z) are shifted. Numbers and symbols stay unchanged.
Result
The result will appear here
Documentation
What is a Caesar cipher?
The Caesar cipher is a classic substitution cipher. It shifts each letter in the plaintext by a fixed offset in the alphabet (with wrap-around) to produce ciphertext.
How it works
For example, with a shift of 3:
A→DB→EZ→C
To decrypt, shift letters in the opposite direction.
Historical background
Named after Julius Caesar, who is said to have used it to protect military messages. It is simple by modern standards but was meaningful historically.
Features
- Simple and fast to encrypt/decrypt
- Low security and easy to brute-force
- Only applies to letters (uppercase/lowercase handled separately)
- Numbers and special characters remain unchanged
Examples
| Shift | Plaintext | Ciphertext |
|---|---|---|
3 | HELLO | KHOOR |
3 | Hello World | Khoor Zruog |
13 | Caesar Cipher | Pnrfne Pvcure |
25 | ABC | ZAB |
Use cases
- Cryptography learning and teaching
- Lightweight text obfuscation
- Games and puzzles
- Historical cryptography research
Security
There are only 25 possible shifts, so it is easy to brute-force. It is suitable for learning and demos, not for real secure communication.
How to use
- Enter text in the input box
- Set a shift (1-25) with the slider or number input
- Click “Encrypt” or “Decrypt” to get the result
- Click “Copy” to copy the result to clipboard