What is the Caesar cipher?

The Caesar cipher is one of the simplest encryption methods. Each letter is shifted by a fixed number of positions in the alphabet.

Is Caesar cipher secure?

No, it's very easy to crack. It's used for educational purposes and fun, not for real security. Use modern encryption for sensitive data.

What shift values should I use?

Any number from 1-25 works. The most famous is a shift of 3 (Julius Caesar's original). Try different values to find one.

Does it work with numbers and symbols?

It preserves numbers and symbols unchanged, only shifting letters. This helps maintain readability.

How do I decrypt a Caesar cipher?

Use a negative shift (e.g., -3 instead of 3) or try all 25 possible shifts until you find readable text.

What's the history of Caesar cipher?

Julius Caesar used this method for military communication around 100 BC. It's one of the oldest known encryption techniques.

Caesar Cipher

The famous shift cipher used by Julius Caesar - encode and decode messages instantly

Adjustable Shift

Use any shift value from 0 to 25

Encode & Decode

Same tool works for both directions

Historic Method

Used by Julius Caesar ~100 BC

Real-time Preview

See results as you adjust the shift

Enter Text 0 characters

Shift Control

Shift Value: 3

3 is Julius Caesar's original shift

Quick Tips

Try all 25 shifts to brute-force
Numbers and symbols stay the same
Case is preserved
Shift 0 = original text

Cipher Methods

Encoding (Encrypt)

Convert plaintext to ciphertext:

Choose a shift value (1-25)
For each letter, count forward by the shift amount
Wrap around after Z back to A
Non-letters stay unchanged

Example: "HELLO" with shift 3 = "KHOOR"

Decoding (Decrypt)

Convert ciphertext back to plaintext:

Use the negative shift (e.g., -3)
Or use shift value 26 - original shift
Count backward by the shift amount
Try brute force with all 25 shifts if unknown

Example: "KHOOR" with shift -3 = "HELLO"

Use Cases

Learning Cryptography

Great introduction to encryption concepts and cipher techniques

Puzzle & Games

Hidden messages, escape rooms, and treasure hunts

Codebreaking Practice

Training for frequency analysis and cryptanalysis

Historic Interest

Explore ancient Roman military communications

Important Notes

Not Secure: Caesar cipher can be easily broken in seconds
Pattern Analysis: Frequency analysis reveals the plaintext
Only 25 Possibilities: Can brute-force all shifts quickly
Educational Use: Great learning tool for cryptography basics

Use Cases: Fun, games, puzzles - not real security
Modern Encryption: Use AES, RSA, TLS for actual data protection
Historical Value: Important in cryptography history
Entertainment Only: Keep for casual obfuscation only

Keyboard Shortcuts

Ctrl + Enter Encode/Decode

Ctrl + Shift + C Copy Result

Ctrl + L Clear All