Semaphore flag alphabet
Convert text to the flag semaphore alphabet and back to letters.
Semaphore flag alphabet
Paste text and this tool converts it into the flag semaphore alphabet used by sailors, scouts and signal corps to send messages across distance with two handheld flags. Each letter becomes a pair of flag positions — the two directions the signaller's arms point to form that letter — and the same table works in reverse to turn a written-down semaphore message back into readable text.
Choose how the flag positions are written with the notation option: direction names like N and SW, clock-hour positions like 6:00 and 7:30 (the way many signalling manuals describe them), or a compact pair of arrow characters for a quick visual read. Letter and word separators are configurable too, so the output matches whatever convention you are transcribing from. Digits are handled with the standard numerals shift — the same two-flag signal used to mark "what follows is a number," with letters A through J standing in for 1 through 9 and 0 — or you can skip digits entirely. Accented letters either fold to their closest plain letter (é becomes E) or are skipped, your choice.
Switch direction to go from semaphore back to text: paste position pairs in the same notation and separators, and the tool reads them back into letters, silently skipping anything it doesn't recognize rather than erroring out. Turn on the plain-letter transcription to see the resolved text printed under an encoded message, and the notation legend to print every letter's flag positions for reference — handy when you're checking your own semaphore against the standard alphabet.
Everything runs locally in your browser; nothing you type is uploaded anywhere. Copy the result, download it as a .txt file, or send it straight back into the input to try another notation on the same message.