How to use the chromatic tuner
- Press Start tuner and allow the microphone.
- Play or sing a single steady note.
- Read the note name, then check the needle: left of centre is flat, right is sharp.
- Adjust your instrument or voice until the needle is in the middle and the note turns green.
- Use Settings to change the reference pitch (A4) or to show black keys as flats instead of sharps.
- A cent is one hundredth of a semitone: the needle shows ±50 cents, halfway to the next note.
- The usual reference is A4 = 440 Hz, but some ensembles use 442 or baroque pitch (415).
- Chromatic tuning works for any instrument that plays one note at a time, including wind, brass and voice.
Note frequencies
With A4 set to 440 Hz, the notes of the middle octave sound at:
| Note | Frequency |
|---|---|
| C4 | 261.63 Hz |
| C♯4 / D♭4 | 277.18 Hz |
| D4 | 293.66 Hz |
| D♯4 / E♭4 | 311.13 Hz |
| E4 | 329.63 Hz |
| F4 | 349.23 Hz |
| F♯4 / G♭4 | 369.99 Hz |
| G4 | 392.00 Hz |
| G♯4 / A♭4 | 415.30 Hz |
| A4 | 440.00 Hz |
| A♯4 / B♭4 | 466.16 Hz |
| B4 | 493.88 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
What is a chromatic tuner?
A tuner that detects any of the 12 notes of the chromatic scale, instead of only the open strings of a particular instrument. It works for any instrument or voice.
What is a cent?
A cent is one hundredth of a semitone. People can usually hear a difference of about 5 to 10 cents, and a tuner is accurate to a couple.
Can I change A4 from 440 Hz?
Yes. Open Settings and change the reference pitch between 415 and 466 Hz, for example 442 Hz for some orchestras.
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. 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.