Morse code detector
A Morse code detector for your microphone. Hold your phone or laptop near the radio, speaker or buzzer, and the dots, dashes and text appear as they are sent. Free, live, and nothing is recorded.
Your browser will ask to use the microphone. The sound is measured here and never recorded.
Decoded text
Play a Morse tone near your microphone to begin…
Detected Morse
…
- Live as it is sentLetters appear as they are sent, the first included
- Finds the tone and speedLearns the speed from every dot, dash and gap
- Test with one devicePlay a test signal through your own speaker
How to use
Press Start listening and allow the microphone. Or press Play a test signal to hear a short call through your own speaker and watch it decode.
Hold the phone or laptop near the radio, speaker or buzzer. The text and the Morse appear as the signal is sent.
Watch the waterfall: the dashed line is the tone being read. Tap another pitch to read that one instead.
Letters missing or extra? Move Sensitivity, or tick Set the speed myself and enter the sender’s speed.
Copy the text or the Morse, press Download text to save it, or open it in the translator to hear it again.
What it does
This Morse code detector listens and writes as it hears:
Live. Letters appear as they are sent, the first one included.
Finds the tone and the speed. It picks the Morse pitch between 300 and 1,500 Hz and learns the speed from every dot, dash and gap.
Shows what it hears. A waterfall of 61 pitches, a level meter with its threshold, and the tone and speed it is reading.
Tone and speed by hand. Tap a pitch on the waterfall or type it, and set the sender’s speed from 5 to 50 WPM.
A test without a second device. Play a test signal sends CQ TEST through your speaker while it listens.
Keeps what it heard. Copy the text or the Morse, save a text file, or open it in the translator.
Your choice of microphone. With more than one, such as a headset or a sound card wired to a radio, pick the one that listens.
How it works
It listens for one pitch, not for loudness, and times everything from the audio itself.
Locks onto the tone
It measures 61 pitches from 300 to 1,500 Hz every 5 milliseconds, shown as the live waterfall, then follows the Morse tone. Voices, hum and hiss at other pitches are ignored.
Tap the waterfall to choose the pitch yourself.
Learns the speed
The speed comes 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) still reads correctly.
Set it by hand and it uses yours.
Writes it out live
Until it is sure it hears Morse rather than static it shows nothing, then reads back everything, first letter included.
A long pause ends a transmission; the next can come at another speed.
Speed is in words per minute by the PARIS standard: one dot lasts 1,200 ÷ WPM milliseconds, and ITU-R M.1677-1 sets a dash at three dots.
Ways to set it up
Anything that beeps at one steady pitch can be read. These three cover most people.
- A radio or receiverTurn the volume up and hold the phone or laptop near the speaker, or use headphones on the radio and the mic close to one earpiece.Fast sending is fine
- A second devicePlay Morse from the translator on another phone and hold the two together: the cleanest test there is.Best first test
- A practice oscillatorA key with a buzzer or a sidetone works as long as it beeps at one steady pitch. Clicks and knocks have no pitch to follow.One steady pitch
Examples
Signals made with the site’s audio engine (most with light hiss), read through the same filter bank the page uses:
| Signal | It reads |
|---|---|
| The test signal: CQ TEST at 18 WPM, 700 Hz | CQ TEST · about 700 Hz · about 18 WPM |
| CQ DE W1AW at 18 WPM, 700 Hz | CQ DE W1AW |
| PARIS PARIS at 5 WPM, 650 Hz | PARIS PARIS |
| PARIS PARIS at 35 WPM, 1,100 Hz | PARIS PARIS |
| SOS SOS at 40 WPM, 800 Hz | SOS SOS |
| TTT at 20 WPM | S: three marks of one length could be dots. Set the speed to 20 and it reads TTT |
| TEST TEST at 1,000 Hz under a louder station at 600 Hz | Follows the louder 600 Hz station; tap 1,000 Hz on the waterfall and it reads TEST TEST |
Have a recording or a video? Use the Morse code audio translator.
Good questions
Frequently asked questions.
About the Morse code detector
How do I detect Morse code with my phone?
Open this page in your phone’s browser, press Start listening and allow the microphone, then hold the phone near the sound. There is no app to install. The text appears as the Morse is sent, and the waterfall shows the tone it is reading.
Why doesn’t it pick anything up?
Usually the tone is too faint or another sound is louder. Turn the source up, move closer, and check that the level meter jumps with each beep.
Raise Sensitivity for a faint signal; lower it if noise turns into letters. If Play a test signal shows nothing, play Morse from a second device: some phones turn the speaker down while the microphone is on.
Can it read Morse code from a recording or a video?
Yes, two ways. Upload the file to the Morse code audio translator, which reads the whole recording and draws a spectrogram. Or play the recording or video next to this page while it listens.
Can it detect a flashing light or knocks?
Not this page: it listens for a beep at one steady pitch, and a knock or a click has none. For a flashing light, use the light translator. For knocks on a wall, the tap code translator listens for knocks.
How fast can it read?
In our tests it reads from 5 WPM to 40 WPM, at pitches from 300 to 1,500 Hz. A very short message can’t show its own speed (TTT reads as S), so tick Set the speed myself and enter it. Machine sending reads best; hand sending with uneven gaps may lose letters.
Is anything recorded?
No. The sound is measured on your device as it arrives and then dropped; only the letters stay on the page until you clear them or leave. Nothing is uploaded, and the test signal is made in your browser too.
Trust and limits
Private by design.
Honest about limits.
On your device
Runs in your browser
The detector runs in your browser, on an AudioWorklet. The microphone’s sound is measured as it arrives and never recorded, stored or uploaded.Know the limits
One tone at a time
It follows one tone at a time between 300 and 1,500 Hz. It can’t read clicks or knocks (they have no pitch), two stations on the same pitch at once, or Morse buried under louder music or speech.Know the limits
Faint on phones
Phones may turn the speaker down while the microphone is on, so the test signal can be faint there.ITU-R M.1677-1
Timing standard
Timing follows ITU-R M.1677-1. Maintained by Translate Morse Code, an independent site; last updated October 2026.