How to use the tuner
- Pick your instrument and tuning, then press Start tuner and allow the microphone.
- Pluck one string at a time and let it ring.
- Left of centre means flat (tighten the peg), right of centre means sharp (loosen it).
- When the note turns green and says In tune, move to the next string.
- Tap a string to lock onto it, or tap ▶ to hear its reference note and tune by ear.
- The tuner is accurate to within about 2 cents in testing on every string of every tuning.
- Your audio is analysed on your device and is never recorded or uploaded.
- It works on phones, tablets and computers, in the browser, with nothing to install.
Standard tuning chart
Guitar (E A D G B E)
| String | Note | Frequency |
|---|---|---|
| 6th | E2 | 82.41 Hz |
| 5th | A2 | 110.00 Hz |
| 4th | D3 | 146.83 Hz |
| 3rd | G3 | 196.00 Hz |
| 2nd | B3 | 246.94 Hz |
| 1st | E4 | 329.63 Hz |
Ukulele (G C E A)
| String | Note | Frequency |
|---|---|---|
| 4th | G4 | 392.00 Hz |
| 3rd | C4 | 261.63 Hz |
| 2nd | E4 | 329.63 Hz |
| 1st | A4 | 440.00 Hz |
Bass (E A D G)
| String | Note | Frequency |
|---|---|---|
| 4th | E1 | 41.20 Hz |
| 3rd | A1 | 55.00 Hz |
| 2nd | D2 | 73.42 Hz |
| 1st | G2 | 98.00 Hz |
Violin, viola & cello (G D A E)
| String | Note | Frequency |
|---|---|---|
| 4th | G3 | 196.00 Hz |
| 3rd | D4 | 293.66 Hz |
| 2nd | A4 | 440.00 Hz |
| 1st | E5 | 659.26 Hz |
Mandolin (G D A E)
| String | Note | Frequency |
|---|---|---|
| 4th | G3 | 196.00 Hz |
| 3rd | D4 | 293.66 Hz |
| 2nd | A4 | 440.00 Hz |
| 1st | E5 | 659.26 Hz |
Banjo (G D G B D)
| String | Note | Frequency |
|---|---|---|
| 5th | G4 | 392.00 Hz |
| 4th | D3 | 146.83 Hz |
| 3rd | G3 | 196.00 Hz |
| 2nd | B3 | 246.94 Hz |
| 1st | D4 | 293.66 Hz |
Tips for an accurate reading
- Pluck one string at a time and let it ring. Muted or buzzing strings are hard to read.
- Use a quiet room. Background music or voices can confuse any tuner.
- Hold the device close to the instrument's sound hole or body.
- Tune up to the note. If you overshoot, go below the note and tighten up to it again.
- Re-check every string once you have finished, as adjusting one affects the neck tension.
How the tuner works
Every note is a vibration with a frequency: A4 is 440 vibrations per second, or 440 Hz. The tuner listens through your microphone and uses a pitch-detection method called YIN to find how often the sound repeats. It compares that frequency with the one the string should have and shows the gap in cents, where 100 cents is one semitone (the step between two neighbouring piano keys). Within 5 cents of the target the note turns green: that is far finer than most listeners can hear.
Troubleshooting
- "The microphone is blocked": open your browser's site settings, allow the microphone for this page, and reload.
- The needle jumps around: let the note ring for a second, mute the other strings and move away from noise.
- It shows the wrong octave or note: pluck more gently, and check the right tuning and instrument are chosen above.
- Nothing happens on iPhone: tap Start tuner yourself; browsers only allow the microphone after a tap.
Frequently asked questions
How does an online tuner work?
It uses your microphone to listen to the note, measures how many times the sound wave repeats each second (its frequency), and compares that with the frequency the note should have. The difference is shown in cents on the needle.
Is it accurate?
Yes. In testing it measured every string of every supported tuning to within about 2 cents, which is much finer than the ear can hear. Real-world accuracy depends on background noise and microphone quality.
Do I need to install anything?
No. It runs in your browser. You only need to allow microphone access when asked.
Is my audio recorded?
No. The sound is analysed live on your device and nothing is stored or sent anywhere.
What if the tuner cannot hear my instrument?
Allow the microphone, get closer to the sound, pluck one string clearly in a quiet room and let it ring. If it still struggles, tune by ear with the reference notes (the ▶ buttons).
More tuners and tools
Guitar tuner, Ukulele tuner, Bass tuner, Violin tuner, Mandolin tuner, Banjo tuner, Chromatic tuner. Once you are in tune, learn the chord shapes in the guitar chord library or the ukulele chord library, find the easiest capo position with the capo calculator, or look up what any set of notes is called with the chord finder.