Cipher Decoding and Encoding Tools
Find your inner spy!
Whether you spell it Cipher or Cypher, you've come to the right place! Our collection of encoding and decoding tools will help you create secret messages, solve puzzles, or simply learn about classical cryptography.
Choose a cipher below to get started encoding and decoding your messages. New: Don't know which cipher was used? Try our Cipher Decoder tool!
Caesar Cipher
The classic substitution cipher used by Julius Caesar. Each letter is shifted by a fixed number of positions in the alphabet.
- Easy to use
- Adjustable shift amount
- Great for beginners
Atbash Cipher
An ancient Hebrew cipher that simply reverses the alphabet. A becomes Z, B becomes Y, and so on.
- No key required
- Self-reciprocal
- Historical significance
Vigenere Cipher
A polyalphabetic cipher that uses a keyword to create multiple shifting patterns, making it harder to crack.
- More secure
- Keyword-based
- Resists frequency analysis
ROT13 Cipher
ROT13 ("rotate by 13 places") is a special case of the classic Caesar Cipher. Instead of selecting your own shift, ROT13 always rotates each letter exactly 13 positions through the alphabet.
- Easy to use
- Caesar Cipher with a fixed key
- Great for beginners
Cipher Decoder New!
Don't know which cipher was used? Our brute force decoder tries Atbash and all 26 Caesar shifts to crack the code!
- Tests 27 methods at once
- Perfect for puzzles
- Instant results
Coming Soon
Introducing: The Cipher Decoder New Tool!
Ever received an encrypted message but had no idea which cipher was used? Our new Cipher Decoder takes the guesswork out of decryption!
How It Works
Simply paste your encrypted text, and the decoder automatically attempts to decrypt it using:
- Atbash Cipher – Tests alphabet reversal
- All 26 Caesar Shifts – Tries every possible rotation
All 27 results are displayed simultaneously in easy-to-scan cards, making it simple to spot readable text among the attempts.
Perfect For
- Cipher puzzles and riddles
- Geocaching challenges
- Escape room clues
- CTF competitions
- Educational exercises
What is a Cipher?
A cipher (also spelled cypher) is a method of transforming text to conceal its meaning. Ciphers have been used throughout history to protect sensitive information, from military communications to personal secrets.
Types of Classical Ciphers
Classical ciphers fall into two main categories:
- Substitution Ciphers: Each letter is replaced with another letter or symbol. Caesar, Atbash, and Vigenere are all substitution ciphers.
- Transposition Ciphers: The letters remain the same but their positions are rearranged.
Don't Know Which Cipher Was Used?
If you have an encrypted message but don't know which cipher was used to create it, our Cipher Decoder tool can help! It automatically tests the most common simple ciphers (Atbash and all Caesar shifts) simultaneously, making it easy to identify the correct decryption method.
Why Learn About Ciphers?
Understanding classical ciphers provides a foundation for learning about modern cryptography. They're also commonly used in puzzle games, escape rooms, geocaching, and educational settings. Whether you're a puzzle enthusiast, a student, or just curious about secret codes, these tools will help you encode and decode messages quickly and easily.
Security Notice
These classical ciphers are for educational and entertainment purposes only. Do not use them for actual security needs. They can be easily broken with modern computing power. For real encryption requirements, use modern cryptographic standards like AES-256.