Microphone Morse Code Decoder
Decode Morse code straight from the air. Allow microphone access, point it at any steady beeping signal, and this tool listens for the tone, measures the dots and dashes, and translates them into readable text in real time.
The red mark is the threshold. It follows the signal by itself.
Raise it for a faint signal, lower it if noise shows up as letters.
Detected Morse
…
Decoded text
Play a Morse tone near your microphone to begin…
How it works
The decoder listens for one pitch, not for loudness. Right on the audio thread, it measures 61 pitches from 300 to 1,500 Hz every 5 milliseconds and shows them as a live waterfall. It locks onto the Morse tone (the dashed line) and follows it, so voices, hum and hiss at other pitches are ignored. Because the timing comes from the audio itself, not the screen, fast sending (40 words per minute and more) reads as well as slow.
The speed is learned from all the dots, dashes and gaps heard so far, never from the first beep, so a message that starts with a dash (T, M, O) reads correctly. Until it is sure it is hearing Morse rather than static it shows nothing; then it reads back everything it heard, first letter included. A long pause ends a transmission, and the next one can come at a different speed.
Tips for a clean read
- Hold the microphone close to a steady, single-pitch tone.
- The red mark on the meter is the threshold, and it sets itself. Raise the sensitivity for a faint signal; lower it if noise shows up as letters.
- Keep the sending speed even — consistent dot, dash and gap lengths decode far more reliably than hand-keyed bursts.
- Try it with another device playing Morse audio from this site for a quick, clean test.