Pitch Detector

Real-time musical pitch detection — free, browser-based

Pitch Detector
Note----
Frequency-- HzHz
Cents--
FlatSharp
Click Start to begin pitch detection.A4 = 440 Hz · C2 – C6

What is a Pitch Detector?

A pitch detector is a tool that listens to audio through your microphone and identifies the musical pitch in real time. This tool uses the YIN algorithm — a precise autocorrelation method — to find the fundamental frequency of your voice or instrument, then converts it to a standard note name (like A4 or C3), frequency in Hz, and a cents offset showing exactly how sharp or flat you are. It runs entirely in your browser with zero latency and no data ever leaves your device.

Features

Real-Time Note Detection
Identifies the exact musical note (C, D, E, F, G, A, B with sharps/flats) instantly as you sing or play.
Frequency Readout
Displays the precise Hz frequency of your pitch alongside the MIDI note number.
Cents Offset Meter
Shows how many cents sharp or flat you are from the perfect pitch — accurate to plus or minus 1 cent.
Piano Roll Visualizer
Scrolling graph plots every detected note as a colored dot on a full chromatic grid from C1 to C7.
Transpose Support
Shift the displayed pitch up or down in semitones to match transposing instruments like Bb trumpet or Eb alto sax.
Adjustable Range and Tuning
Set A4 anywhere from 415 Hz to 466 Hz, choose label style (C D E, Do Re Mi, or numbers), and pick your octave range.

How to Use

  1. 1

    Open this page in a browser that supports the Web Audio API (Chrome, Edge, Firefox, Safari).

  2. 2

    Click anywhere on the piano roll or the play button to begin. The browser will ask for microphone permission — allow it.

  3. 3

    Sing a note, play an instrument, or whistle. The note name, frequency, and cents offset appear instantly.

  4. 4

    Watch the colored dots trail across the piano roll to see your pitch history over the last 10 seconds.

  5. 5

    Click the canvas again to pause and inspect the frozen dots. Click once more to resume.

  6. 6

    Use the settings gear to change tuning reference (A4), note label style, octave range, or transpose.

Frequently Asked Questions