CipherSteps

CipherSteps

Cipher encoders and decoders

Choose from 16 classic ciphers and codes. Encode a message, follow the letter steps, or decode a puzzle with a known rule.

Codes

A1Z26

Turn letters into numbers, or read a number puzzle one letter at a time.

Open A1Z26

Substitution

Atbash

Reverse the alphabet to encode a message. Apply Atbash again to decode it.

Open Atbash

Substitution

Beaufort cipher

Subtract each message letter from its key letter, then use the same rule to decode.

Open Beaufort cipher

Substitution

Caesar cipher

Shift the alphabet, check each letter, and try all 26 shifts when you do not know the key.

Open Caesar cipher

Substitution

Gronsfeld cipher

Use a repeating digit key to give each message letter its own small shift.

Open Gronsfeld cipher

Codes

Morse code

Translate dots and dashes, then listen at a speed that suits you.

Open Morse code

Grids

Playfair

Build a keyed square and follow each letter pair, including any added fillers.

Open Playfair

Transposition

Rail Fence

Write letters in a zigzag, then read across the rails to rearrange the message.

Open Rail Fence

Substitution

ROT13

Shift each letter by 13 places. Run the result through ROT13 again to read it.

Open ROT13

Transposition

Scytale

Choose a grid width, write across the rows, and read down the columns.

Open Scytale

Substitution

Vigenère cipher

Repeat a letter key across your message and follow the changing shifts.

Open Vigenère cipher
Classical ciphers for learning and puzzles

Not for protecting confidential information.

Cipher rules and reference guides →