Guitar Tuner
A chromatic tuner for guitar, bass, ukulele and violin. Pitch is detected from your microphone entirely on your device — no audio is ever uploaded.
The tuner isn’t available here
Your browser doesn’t support microphone capture (getUserMedia) or the Web Audio API. Try the latest Chrome, Edge, Firefox, or Safari. Note: the microphone requires a secure context (https or localhost).
Microphone permission was denied
The tuner needs your microphone to hear the instrument — the audio is analyzed locally and never recorded or sent anywhere. Allow microphone access for this site in your browser’s address-bar permissions, then try again.
Ready to tune
Click below and allow microphone access. Your browser will analyze the sound in real time using autocorrelation — nothing is recorded or uploaded.
The string nearest to what you’re playing lights up; it turns green when you’re within ±5 cents.
How it hears your pitch
The tuner reads the raw waveform from your microphone and runs autocorrelation — sliding the signal against itself to find its repeating period — with parabolic interpolation for sub-sample precision and a clarity threshold so noise doesn’t fake a reading. It compares the result to the nearest equal-temperament note (using your A4 calibration) and shows the offset in cents. All of it runs ~30 times a second, locally, with no servers involved.