Tap Code Translator
Encode and decode tap code — the 5×5 'knock' code shown as groups of taps — famously used by prisoners of war to communicate.
What is tap code?
Tap code is a way of spelling out letters using a 5×5 grid and simple taps or knocks. The first group of taps gives the row and the second gives the column. The letter K is dropped and written as C so that all 25 remaining letters fit the grid. It became famous among prisoners of war, who tapped messages through walls.
How to use it
- Choose Encode or Decode.
- Type your message, or paste tap groups to decode.
- Tap Copy to save the result.
How tap code works
Each letter shows as two groups of dots — for example two dots, a pause, then three dots means row 2, column 3, which is the letter H. Letters are separated by slashes so you can read the taps clearly. Decoding counts the dots in each group back into a row and column.
Where it is used
Tap code appears in history lessons, puzzles, and escape rooms, and it is a memorable demonstration of how much can be communicated with only knocks.
More codes and ciphers
Explore the rest of the family: the Caesar Cipher, Atbash, Vigenère, and A1Z26. For other encodings, try the Morse Code Translator and the Binary Translator.
Free and private
This tap code tool runs entirely in your browser — free, with no sign-up, and nothing you type is uploaded or stored.
Frequently asked questions
- What is tap code?
- Tap code encodes letters using a 5×5 grid: the first group of taps gives the row and the second gives the column. The letter K is dropped and written as C, so all 25 remaining letters fit the grid. It became famous among prisoners of war.
- How is tap code shown here?
- Each letter is displayed as dots — for example two dots, a pause, then three dots means row 2, column 3. Letters are separated by slashes so you can read and reproduce the taps.
- How do I decode tap code?
- Choose Decode and paste the dot groups (letters separated by slashes). The tool reads each row/column tap pair back into a letter.
- Is it free and private?
- Yes — it runs entirely in your browser with no sign-up, and nothing you type is uploaded.
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