Morse Code Decoder
Tap out dots and dashes on an on-screen key and see them turn into letters as you go. The same tool can also listen to beeps through a microphone or read a sound file.
Opens Unscramble Words 4U, our free word-puzzle site, in a new tab. Free, with no sign-up.
What it does
The Morse Code Decoder on Unscramble Words 4U has three tabs. Key it gives you a large button: a quick tap makes a dot, a longer hold makes a dash, and on a computer the space bar does the same job. While you send, it shows the pattern of the current letter, and when you pause it settles on a letter. Listen uses the microphone to pick up Morse played nearby – from a buzzer, a radio, a phone or a video – and decodes it live. Upload audio opens a recording from your device and shows the text with times, so you can click a word to hear that bit again.
Because it measures your actual beeps and gaps, the decoder works out your speed for itself and copes with slow or slightly uneven sending. There are options to choose a starting speed, let it adapt to you, and hear a beep while you key. It also reads the Greek, Russian, Hebrew, Arabic, Persian, Korean SKATS and Japanese Wabun Morse systems if you choose one first. It is a good fit for learners who want instant feedback on whether their sending is readable.
How to use it
- Open the decoder and choose a tab: Key it, Listen (microphone) or Upload audio.
- If you are not using English letters, pick the right system from the Alphabet menu before you begin.
- Key it: tap the big key briefly for a dot and hold it for a dash. Pause for roughly three dots’ worth to finish a letter, and longer to finish a word.
- Listen: press Start listening and allow microphone access when the browser asks. Play the Morse close to the microphone. You can let it find the tone and speed or set them yourself, and adjust the sensitivity.
- Upload audio: choose a file (such as MP3, WAV, OGG, M4A or WebM) or drag it in, or press Try a sample to see how it works.
- Copy the decoded text, or in the Listen and Upload tabs download it as a .txt file.
More tips
- Tick ‘Beep while keying’ so pupils hear their own rhythm – it makes the link between sound and symbol much clearer.
- For listening mode, a quiet room and one clear tone work best. Talking over the beeps confuses it.
Ideas for the classroom and home learning
- KS1 (5–7)Teach E (one dot) and T (one dash), then let children take turns keying them on the interactive whiteboard to see the letter appear.
- KS2 (7–11)Keying relay: each pair sends a short word on the decoder while the class writes down what they think it is, then checks the screen.
- KS3 (11–14)Science of sound: one pupil plays Morse from the translator on a second device while the decoder listens. Change the distance, volume and background noise and record when decoding fails.
- KS4 (14–16)Computing: discuss how software might tell a dot from a dash when people’s timing varies, and why measuring relative lengths beats fixed timings.
Questions
Does the microphone record pupils’ voices?
According to the tool, the microphone is only switched on after you press Start and give permission, and the sound is analysed in the browser as it arrives – it is not recorded, stored or uploaded. Uploaded files are also opened on the device.
How long is a dash compared with a dot?
Roughly three times longer. Allow about three dot-lengths of silence after a letter and around seven after a word.
What sort of files can it read?
Common formats such as MP3, WAV, OGG, M4A and WebM open in most browsers. The tool accepts recordings of up to roughly 30 minutes or 100 MB.
Is this the same as the audio decoder page?
The audio decoder focuses on recordings and the microphone, with extra advice for radio users. This page adds the tappable key, so it is the better choice for learning to send.
Opens Unscramble Words 4U, our free word-puzzle site, in a new tab. Free, with no sign-up.
Microphone use needs permission in the browser, so agree with your school’s device policy first. Morse is easy for anyone to read, so it is not a safe way to hide personal information.