Free online cipher tool
Secret Code Maker
Turn a note into a playful code in seconds. Pick a cipher, type your message, and copy the result.
View the Classic cipher key
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| Code |
Your message stays in this browser. This tool makes puzzles, not secure encryption.
Three simple steps
How the secret code maker works
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01
Choose a cipher
Each themed cipher uses a different substitution alphabet. Your friend must choose the same one to decode the message.
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02
Write your message
Letters, numbers, and common punctuation are swapped instantly. Spaces, line breaks, emoji, and unsupported symbols remain unchanged.
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03
Copy or print it
Send the coded result to a friend or print it as a puzzle. They can return here, select Decode, and reveal the original note.
Make it a game
Fun ways to use secret messages
A secret message generator can turn an ordinary note into the start of a puzzle. Use it for scavenger-hunt clues, classroom warmups, birthday surprises, escape-room challenges, or coded friendship notes.
The five ciphers give the same message different results, which makes it easy to create several clues without changing tools. Print the cipher key for younger solvers or hide it when you want a harder challenge.
Clvvs, Jlybsa!
Answer: Hello, World!
A code, not a lock
What is a substitution cipher?
A substitution cipher replaces each character with another character according to a fixed key. In the Classic cipher, for example, “Hello” becomes “Clvvs.” The pattern stays consistent, so the coded message can be changed back when the same key is used.
These codes are excellent for games and learning, but they are easy to analyze and should not protect sensitive information. For passwords, financial data, or private records, use modern security tools designed for real encryption.
Questions and answers
Secret code maker FAQ
Is this secret code maker secure encryption?
No. It creates classic substitution puzzles for entertainment. Do not use it for passwords, financial details, personal records, or other sensitive information.
Does SecretCode.me store my message?
No. The message is changed inside your browser and is not submitted to SecretCode.me. Reloading or leaving the page clears the text.
How can a friend decode my message?
Tell your friend which cipher you used. They can paste the coded message above, select the same cipher, and choose Decode.
Why did some characters stay the same?
The ciphers replace English letters, numbers, and several common punctuation marks. Other characters, including most emoji and accented letters, are preserved so your message is not damaged.