Codes & Ciphers

Many puzzles use codes and ciphers to conceal clues or make the puzzle harder. Herein you will find a collection of tools to help you encode, decode, encrypt and decrypt messages using a variety of techniques.

Monoalphabetic Ciphers

These types of ciphers substitute one letter for another letter throughout the entire message. Because the same substitution applies for the entire message, these ciphers are relatively easy to crack using frequency analysis and educated guesses.

Also see the Codes section for monoalphabetic substitution ciphers where the substitution is in the form of a different alphabet.

Polyalphabetic Ciphers

In these ciphers, one letter is substituted for another, but that substitution may change throughout the message. These types of ciphers are bit more tricky to crack if you don't know the method.

Polygraphic Ciphers

These ciphers perform substitutions on groups of two or more letters instead of single letters.

Transposition Ciphers

A transposition cipher keeps the letters in the message the same, but rearranges them according to some algorithm. It's an anagram! For short messages, this is not very effective, but for longer messages it can be difficult to unscramble the message.


A code is a form of substitution cipher where letters or words are switched to predefined alternates. Codes are not intended to conceal the message, but rather to transform it to be more easily communicated or for artistic reasons.

Other Ciphers

There are other types of unique ciphers that don't fall into the above classifications.


Here is a collection of general purpose tools that can be used to crack a code if you don't know what algorithm was used.