How to use
- Choose your instrument and tuning — standard guitar tuning is selected by default.
- Click Start tuning and allow the browser to use the microphone.
- Pluck one string and let it ring. The tuner picks the nearest string; tighten the string if the needle is left of centre, loosen it if it is right, until it turns green.
- Repeat for each string. Tap a string name below to hear its reference note.
Options explained
- Cents (¢)
- A semitone is 100 cents. Within ±5 cents is shown as in tune — most people cannot hear a smaller difference.
- Reference A4
- The pitch the other notes are calculated from, 440 Hz by default. Change it to 432 Hz or another value to match a recording or another instrument.
- Chromatic
- Shows the nearest note of the twelve-tone scale for any sound, for violins, voices or tunings not in the list.
Target notes and frequencies
The tuner works out each target from the reference pitch with frequency = A4 × 2^((note − 69) ÷ 12), where note is the MIDI note number. With A4 at 440 Hz, the strings of the tunings in the list are as follows, listed from the lowest string to the highest (for the ukulele, in string order G C E A).
| Tuning | Notes | Frequencies (Hz) |
|---|---|---|
| Guitar, standard | E2 A2 D3 G3 B3 E4 | 82.41, 110.00, 146.83, 196.00, 246.94, 329.63 |
| Drop D | D2 A2 D3 G3 B3 E4 | 73.42, 110.00, 146.83, 196.00, 246.94, 329.63 |
| DADGAD | D2 A2 D3 G3 A3 D4 | 73.42, 110.00, 146.83, 196.00, 220.00, 293.66 |
| Open G | D2 G2 D3 G3 B3 D4 | 73.42, 98.00, 146.83, 196.00, 246.94, 293.66 |
| Ukulele | G4 C4 E4 A4 | 392.00, 261.63, 329.63, 440.00 |
| Bass, 4-string | E1 A1 D2 G2 | 41.20, 55.00, 73.42, 98.00 |
The needle shows 1200 × log2(heard ÷ target) cents, so being 10 cents sharp means the pitch is about 0.6% above the target.
Frequently asked questions
The needle jumps around or nothing is detected. What can I do?
Pluck firmly, mute the other strings with your hand and keep the instrument close to the microphone. Background music or talking confuses pitch detection. Low bass strings need a few seconds of steady sound.
How accurate is it?
Pitch detection uses the YIN algorithm and resolves well under one cent on a clean note; the result is averaged over the last few readings to keep the needle steady. Laptop microphones that filter low frequencies can make the bass E string harder to pick up.
Does it work for ukulele and bass?
Yes. Choose Ukulele (G C E A, standard re-entrant tuning) or Bass – 4-string (E A D G). For other instruments use Chromatic.
Does it record me?
No. The sound is analysed live in your browser while the tuner is on; nothing is stored or uploaded.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.