Instrument Tuner (Pitch Detection)
Tune your guitar, violin, or any other instrument using your device's microphone. The tool analyzes the sound in real time, identifies the note played, and displays the offset in cents from the exact note to guide you.
How It Works
Once microphone permission is granted, the captured sound is continuously analyzed by autocorrelation: the signal is compared to time-shifted versions of itself, and the shift that produces the best match reveals the period — and therefore the frequency — of the fundamental sound. This frequency is then converted into a musical note (C, D, E...) and octave, along with the offset in hundredths of a semitone (cents) from the exact frequency of that note in standard tuning (A4 = 440 Hz).
What does the offset shown in cents mean?
A cent is one hundredth of a semitone. An offset of 0 means you are perfectly in tune. A positive offset means the note played is slightly too high (sharp) relative to the target note; a negative offset means it is too low (flat). An offset of less than about 5 cents is generally considered in tune to the ear.
Why is detection unstable or not working?
Autocorrelation pitch detection works best on a clear, sustained sound (one note at a time, without chords or significant background noise). A noisy environment, a poor-quality microphone, or a note that is too quiet can make detection unstable or prevent it entirely — in that case, no note is displayed until the signal is strong and clear enough.
Privacy: audio captured by your microphone is processed only locally, in real time, to calculate the detected frequency. It is never recorded, never saved, and never sent to a server. The microphone stream is cut off immediately as soon as you click 'Stop' or leave the page.