Morse Code Audio Translator: Sound to Text and Text to Sound

How to translate Morse code audio to text

The quickest way to decode Morse code audio is to let the tool hear it: either through the microphone while another device plays the beeps, or from a recording you upload. Both routes end in the same place, a line of dots and dashes above the decoded text.

1. Tap Start listening and allow the microphone when the browser asks. The status line confirms when sound is reaching it.
2. Play the complete message on a second device, or open Upload a recording and drop in the file.
3. Watch the result build as the signal arrives. Letters appear as each character's beeps finish.
4. Tap Stop listening, then Copy text or Download text (.txt). Shaded letters need a second look; tap one to compare possible readings.

If you have nothing to test with, Try a sample plays a known phrase, I LOVE YOU at 10 WPM and 600 Hz, so you can see the decoder working before you trust it with your own recording.

Listening through the microphone

Live decoding works in real time, but the microphone is the part most people get wrong. The page asks the browser to switch off echo cancellation, noise suppression and automatic gain control, because those filters are tuned for voices and can swallow a steady tone. If the browser keeps them on anyway, you will see a warning: hold the phone close to the speaker in a quiet room.

Keep one tone in the room. Music, speech or a second signal overlapping the beeps is the most common reason a live session produces gibberish. The 40-bar meter under the status line shows volume only; a full meter does not mean the decoder has locked on. Record 10 s, then decode is a useful middle path when the live result keeps changing, because it captures a short clip and analyzes it in one pass.

Uploading a recording

Any audio format your browser can play will decode, up to 20 MB and three minutes. That covers a phone voice memo, a ham radio clip, a training file or a signal generated by a script, as long as the Morse tone is the loudest thing in it.

Mono recordings with little background noise give the cleanest result. A stereo file still works; the decoder reads the first channel.

Morse code sound generator: text to Morse audio

Morse code sound is made in the second pane, Text → sound: type a message of up to 1,000 characters and press Play. Letters, numbers and common punctuation such as ? / @ = + are encoded; a character outside the table shows as # in the code line so you can spot it.

1. Switch to Text → sound and enter your message.
2. Pick a speed chip, or leave it at 10 words per minute (WPM) for a microphone test. Letter spacing follows the speed automatically.
3. Open Advanced sound settings if you want longer gaps for practice, a different pitch, or a telegraph click instead of a clean tone.
4. Press Play on this device, or save a WAV or MP3 to play elsewhere.

Exports are rendered at 44.1 kHz on your device, with the speed, spacing, pitch and waveform you set baked into the file. A study clip, a ringtone or a signal for someone else's decoder all come out of the same button.

How the translator finds the tone and speed

The decoder never asks you what frequency or speed the signal uses; it measures both. For a file, it scans 300 to 1,200 Hz in 20 Hz steps with a Goertzel filter and keeps the frequency with the most energy. For the microphone, it watches 400 to 1,000 Hz and picks the band whose level rises and falls the most, which is what a keyed tone does and background hum does not.

Once the tone is known, every frame is marked on or off against a threshold set from the signal's own peak, so a quiet recording is judged on its own scale. The on-runs are then split into two clusters by duration, short ones become dots and long ones dashes, and the gaps are anchored to the 1, 3 and 7 unit spacing of International Morse. The dot length that falls out of this is converted to WPM with the standard 1,200 ÷ WPM rule, which is why a 10 WPM file reports dots of about 120 ms. A manual speed fixes that dot length instead of estimating it.

Settings explained

Automatic detection is on by default, and most recordings decode without touching anything. The controls under Advanced detection settings and Advanced sound settings exist for signals you already know, such as a file you generated at a fixed tone and speed.

Reset to automatic clears any manual tone or speed. The telegraph click option plays a short 900 Hz tap when a symbol starts and a 700 Hz tap when it ends, which is how a mechanical sounder is heard rather than a continuous beep.

Wrong letters? Causes and fixes

A wrong result almost always traces to one of six causes, and the fix is usually on the page rather than in a different recording. Work down the table from the top; the first two rows cover most cases.

If none of these help, open Wrong result? and save a signal report. It contains timing measurements only, no audio, and it is not sent anywhere unless you choose to share it.

Who uses a Morse code audio translator

Ham radio operators use a Morse code translator with audio input to check their own CW sending or to read a recorded contact without copying by ear. Students and anyone training their ear can generate a clip at 10 WPM, play it on a second device, and confirm the decoder hears what they intended to send.

Puzzle and escape room designers verify that an audio clue actually resolves to the right word. Developers testing a Raspberry Pi buzzer or a Python script point the microphone at the hardware and compare the decoded text with the input. Archivists and teachers use the upload route for old recordings and classroom demonstrations, where a clean WAV gives the most dependable read.