Free Online Mandolin Tuner
Play one string of a pair, see exactly how in tune you are.
A simplified preview of what the Tunable app does. Get the full app
Left to right: 4th string, the thickest, to 1st, the thinnest. Tune one string at a time.
Allow microphone access to begin
How to use this tuner
Click Start Tuning and allow microphone access. Pick one string of a course, mute its partner with a spare finger, and play it. The tuner shows how sharp or flat you are in cents.
The bar spans −50 to +50 cents. Zero is perfectly in tune. Mandolin strings are short and under high tension, so a hard pick stroke reads sharp for an instant; the history line shows the note settling to its real pitch.
The tuner reads against the nearest open string of Standard tuning (G3, D4, A4, E5), so the cents value is the distance to that string, not to the nearest chromatic note. Tap a string to hear its reference pitch and lock the tuner to it; tap again to release.
Mandolin is already selected. It is a concert-pitch instrument, tuned exactly like a violin, so no transposition is applied and the note names are the sounding notes.
Default is A440. Tap + / − to match your ensemble, A441–442 is common in orchestras, A415 for historical pitch.
Standard mandolin tuning is G3, D4, A4, E5 from the lowest course to the highest, the same four pitches as a violin, in fifths. Each course is a pair of strings tuned in unison, so there are eight strings but only four target notes, and the buttons above the display show those four. Tune each string of a pair on its own: rest a spare fingertip on the other string of the course so only one sounds, get it to zero, then do its partner. Two strings that are each in tune with the tuner will be in tune with each other; two strings tuned to each other by ear can both be off by the same amount.
Mandolin strings are short, thin, and tightly wound, which makes them the most sensitive strings on this site to how you play them. A firm pick stroke stretches the string enough to read a few cents sharp for the first fraction of a second, and the note then drops to its resting pitch. Read the settled value, not the attack: on the history line that is the flat part of the trace after the initial hook. Play at the volume you actually perform at, because a string tuned to a gentle stroke will read sharp when you dig in for a chop chord.
The E course is the one most players fight with. Those strings are the thinnest on the instrument and break easily if the peg is turned the wrong way, so tune up to the pitch from below in small moves rather than overshooting and coming back down. If the tuner shows E5 wandering after every retune, the string is still stretching, or the loop end is settling on the tailpiece hook; play for a minute and check again. New sets need several rounds of tune, play, retune before the history line stops sliding.
Bluegrass players tune to A440 and check against the fiddle or the bass in the group. Some players raise the reference slightly for a brighter sound on stage, and Irish sessions tuned to a concertina or flute sometimes sit at A442. Use the A = control rather than tuning every string a little sharp by ear. For chord work, check the intonation at the twelfth fret as well as the open strings: if the open course is at zero but the twelfth-fret note reads sharp, the bridge needs moving back a fraction, not the tuning pegs.
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