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A secret-message maker for kids

Mystery Decoder

Type any message. Send it instantly or print it for screen-free play.

Free · unlimited puzzles
Easy · Mixed Letters

CLASSIFIED

A mystery for a clever decoder

Top Secret Message

YQQF YQ NK FTQ OAGOT RAD KAGD ZQJF OXGQ!

Starter hint: M becomes Y

Crack the code. Reveal the message.cluepopgames.com
Grown-up key · Keep hidden

ANSWER KEY

Easy · Mixed Letters

Top Secret Message

A→MB→NC→OD→PE→QF→RG→SH→TI→UJ→VK→WL→XM→YN→ZO→AP→BQ→CR→DS→ET→FU→GV→HW→IX→JY→KZ→L
The secret message

Meet me by the couch for your next clue!

Make it fun: offer one letter from the key whenever your decoder gets stuck.

For the grown-up's eyes only.cluepopgames.com

Need it now? Play instantly.

Want them off the screen? Print it.

Unlimited Decoder puzzles, printable packs, and every CluePop game are free.

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Who should play Mystery Decoder next?

Free for kids, adults, and families. No signup required.
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Challenge links contain a random device code—not your name, email, or game answers.

Free game guide

How to play Mystery Decoder

Turn any short message into a mixed-letter, hieroglyphic, or squiggle-code puzzle for kids, adults, or families to solve on a phone, tablet, or printed page. It works in a modern browser with no download, payment, or required account.

100% free 5–20 minutes Play immediately
CluePop Mystery Decoder showing a secret message written in squiggle symbols
A real CluePop game view.

Four quick steps

  1. Type a message and choose a code style.
  2. Choose phone, tablet, or printable play.
  3. Share the puzzle while keeping the answer key.
  4. Use optional hints if the solver gets stuck.

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