About & Methodology

How the tuner detects pitch

When you start the tuner, your browser’s microphone streams audio into the Web Audio API. We apply a high-pass and low-pass filter to focus on the guitar’s range and reject rumble and hiss, and an RMS noise gate so background noise doesn’t trigger a false reading. The filtered signal is analysed with the YIN pitch-detection algorithm (via the open-source Pitchy library), which estimates the fundamental frequency and a clarity score. We only display a note once clarity passes a confidence threshold, which is why the readout stays stable instead of jumping around.

How we calculate frequencies (A440)

Every target pitch is derived from A4 = 440 Hz (concert pitch) using twelve-tone equal temperament. The frequency of any note n semitones from A4 is:

So Standard E’s low string (E2) is three semitones plus two octaves below A4 — about 82.41 Hz — and the tuning meter reports how many cents (hundredths of a semitone) your string is above or below that target. In tune is within ±5 cents.

Privacy & zero ads

All audio is processed locally in your browser — your microphone stream is never recorded, uploaded, or sent to a server. The tuner works on any modern phone or desktop browser, and there are no ads, sign-ups, or paywalls.

Our tuning & song data

Each tuning lists its exact string notes low to high with per-string target frequencies. Song pages map a track to the tuning it was recorded in and show the same note-by-note targets, so you can tune up and play along. Alternate and one-off tunings show each song’s own exact notes rather than a generic default. Spotted something wrong? We continually refine the catalog for accuracy.