The microphone is only switched on when you press Start tuner, and the sound is analysed live on this device. Nothing is recorded or sent anywhere.
How to tune
Choose your instrument, press Start tuner and allow the microphone. Pluck one string and let it ring. The tuner shows the nearest note, how many cents it is off and which string it matches. If the needle sits left of centre the string is flat, so tighten it a little; right of centre is sharp, so loosen it. Within five cents counts as in tune. A quiet room and a phone or laptop held close to the instrument give the steadiest reading.
Tuning by ear
Tap any string button to hear its reference note, then match your string to it. This works without a microphone, which is handy on devices that don’t have one or when you would rather not allow access. All notes use the standard pitch of A = 440 Hz.
How the pitch is measured
The tuner compares the sound with slightly delayed copies of itself to find the length of one vibration, a method known as YIN, and refines it to a fraction of a sample. That gives the frequency to well under a cent on a clean note. Strong overtones, a dying string or background noise can make the reading jump, so pluck firmly and read the note while it rings.
A metronome that stays steady
Each click is scheduled ahead of time on your browser’s audio clock rather than with page timers, so the beat stays even when the page is busy. Choose a tempo from 30 to 300 BPM, a time signature and whether beat one is accented. In 6/8 each click is an eighth note, with a lighter accent on beat four. Tap tempo sets the speed from a few taps along with a song.