A guitar tuner that never uploads the mic
This is a chromatic guitar tuner that runs entirely in your browser. It uses the microphone, finds the pitch, and shows the nearest note plus the cents. There is no app to install, no account, and no audio leaves your device.
Standard tuning is the usual E A D G B E. Drop D lowers the lowest string to D. Chromatic mode will name any note, which helps when a string is far from its target or you are tuning to something else.
Standard tuning and drop D
Frequencies below are for A4 at 440 Hz. If you set A4 to 432, every target moves with it.
| String | Standard | Drop D | Hz at 440 |
|---|---|---|---|
| 6 | E2 | D2 | 82.41 or 73.42 |
| 5 | A2 | A2 | 110.00 |
| 4 | D3 | D3 | 146.83 |
| 3 | G3 | G3 | 196.00 |
| 2 | B3 | B3 | 246.94 |
| 1 | E4 | E4 | 329.63 |
How to read the cents
A cent is one hundredth of a semitone. Zero means the note is in tune with the chosen A4. A positive number is sharp. A negative number is flat. The needle covers 50 cents either side, which is half a semitone.
New strings and a cold guitar drift. Tune up to the note rather than down onto it, then play a chord and check the strings that moved.
440 and 432
A4 is 440 Hz unless you change it. 432 is there as a preset, and you can type any reference from 415 to 466 Hz. The note names stay the same. Only the target pitch moves.
Use one reference for the whole instrument. Mixing 440 and 432 across a set of strings will not sit in tune with itself.
A steadier reading
Pluck once, near the twelfth fret, and mute the other strings. A noisy room or a ringing open chord makes the pitch jump. Tuning pegs that slip should be brought up to pitch again after a minute.
Phone speakers and a loud amp in the same room can confuse the mic. Tune unplugged, or point the phone at the guitar rather than the speaker.