Encode and decode
Transform text without leaving your browser.
Pick a cipher, tune the key, paste your message, then copy the result. Punctuation can be preserved for readability or stripped when you want cleaner puzzle text.
Classical ciphers, explained
Cipher Workbench.
Encode, decode, compare, and break approachable ciphers in one local browser lab. Use it as a puzzle helper, classroom reference, quick cryptogram desk, or plain-English guide to how Caesar, Atbash, Vigenere, Rail Fence, Playfair, substitution, and Morse systems actually move text around.
Security note
Classical ciphers are useful for learning, games, and puzzles. They are not encryption for private data, passwords, financial records, or anything that needs real security.
Frequency analysis
Look for patterns before guessing keys.
Classical ciphers leak structure. Frequency, repeated letters, and short brute-force lists often reveal where to start.
Letters0
Unique0
IOC0.000
Reference desk
Know what each cipher is good for.
Use this as a quick field guide: how the cipher works, the key it needs, where it shines, and why it falls apart.
Alphabet map
See the active substitution at a glance.
The map follows the cipher settings in the workbench. It is especially useful for Caesar, ROT13, Atbash, and simple substitution.