Tuner
Tune any instrument with your microphone, with presets for guitar, bass and ukulele.
Sound is analyzed inside your browser and is never uploaded.
How to use
Press Start tuner and allow the microphone. Play one note at a time close to the microphone and let it ring. The tuner shows the note name with its octave, the frequency in hertz and how many cents it is off.
The needle leans left when the note is flat and right when it is sharp. Tune up when it reads Too low and down when it reads Too high. When the note stays within 5 cents of the target, the display turns green and reads In tune. One semitone is 100 cents.
For guitar, bass or ukulele, pick the instrument. The tuner targets the closest string automatically, or you can tap a string to lock it while you tune that one. Each string is marked once it has been in tune.
A4 is 440 Hz by default. If your band, orchestra or a recording uses a different reference such as 442 Hz, set it with the A4 buttons. The instrument and A4 choices are remembered in this browser.
FAQ
Why does the tuner jump between notes or show the wrong octave?
Plucked strings start with a burst of overtones, and low strings have weak fundamentals on small speakers and phone microphones. Pluck softly with the flesh of your thumb, mute the other strings and let the note ring for a moment after the attack. Choosing the instrument preset also narrows the range the tuner listens to.
What are cents?
A cent is one hundredth of a semitone, so 12 semitones make 1,200 cents in an octave. The needle covers 50 cents either side, which is the halfway point to the next note. Within 5 cents the note reads as in tune.
What is A4 = 440 Hz and should I change it?
A4 is the A above middle C, and 440 Hz is the standard concert pitch defined in ISO 16. Some orchestras tune slightly higher, often 442 Hz. Change it only to match other instruments or a recording, and keep 440 Hz otherwise.
Why does the tuner turn off noise suppression?
Noise suppression and automatic gain are made for voice calls and can cut overtones or pump the volume, which confuses pitch detection. The tuner asks the browser to turn them off, so a quiet room gives the steadiest reading.
Does it work on a phone?
Yes. Allow the microphone when asked and hold the phone close to the instrument. On a phone, low bass notes can read less steadily because small microphones pick up little energy below about 100 Hz, so playing the 12th fret harmonic gives the same note an octave higher and is easier to detect.