Music Note Detector
What note is that? Find out instantly. Sing, play, hum, or upload an audio file and see the musical note displayed in the biggest font possible. Cents deviation, interactive piano keyboard, reference tone playback, and note history. 100% browser-based, private, no downloads.
Music Note Detector Tool
How to Use the Music Note Detector
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Click Start Listening
Click "Start Listening" and allow microphone access. Select your preferred input device from the dropdown. All processing runs 100% locally in your browser -- nothing is uploaded.
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Play or Sing a Note
Produce a sound -- sing, hum, play an instrument, or whistle. The detector works best with single, sustained notes. For chords or complex audio, try the Frequency Detector.
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Read the Giant Note Display
The detected note (e.g. C#4) appears in a massive display. The cents deviation bar shows how sharp or flat you are. The corresponding piano key lights up. Click Freeze to lock the display.
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Use Reference Tone & History
Click "Play Reference Tone" to hear the nearest correct note. Watch the note history stream for the last 20 detected notes. Click any piano key to hear that note. Export your session as CSV.
Frequently Asked Questions
What notes can this detect?
The Music Note Detector identifies notes from approximately C1 (32.7 Hz) to C8 (4186 Hz), covering the entire piano range and beyond. The 3-octave keyboard displays C3 to B5, but detection works across the full spectrum. It works with any pitched sound: voice, guitar, piano, violin, flute, trumpet, and more.
How accurate is the note detection?
The YIN pitch detection algorithm with parabolic interpolation achieves ±1–2 cents accuracy for clear, sustained tones. That is 1/100th of a semitone. For best results, use a close microphone in a quiet room and adjust the Sensitivity slider or use the Calibrate button to suppress background noise.
What is the difference between this and the Pitch Detector?
The Music Note Detector is focused on one thing: answering "What note is this?" with the biggest, clearest display possible. The Pitch Detector has more advanced features like pitch stability tracking, vocal range identification, target note mode, note streak gamification, and a scrolling pitch timeline. Use this tool for quick note identification; use the Pitch Detector for in-depth practice and analysis.
Can I upload an audio file instead of using the microphone?
Yes! Drag and drop any audio file (WAV, MP3, OGG, FLAC, M4A) onto the upload zone, or click to browse. The tool analyzes the file locally using an OfflineAudioContext and shows the dominant note. This is useful for identifying notes in recordings without needing a microphone. The file never leaves your browser.
What does the cents deviation bar show?
The cents bar shows how far the detected pitch is from the nearest perfect note. The center (0 cents) means perfectly in tune. Left means flat, right means sharp. The bar is color-coded: green for within ±5 cents (in tune), yellow for ±5–20 cents (close), and red for beyond ±20 cents (off). One cent is 1/100th of a semitone.
Is my audio data private?
Your audio is 100% private. All note detection runs entirely in your browser using the Web Audio API. No audio is recorded, stored, or transmitted to any server. The tool works completely offline once the page is loaded.
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