Ukulele Tuner

Small instrument, small margins

A ukulele has only four strings and a short scale, so every one of them matters. When a single string sits ten cents flat, a chord that would have been bright turns slightly sour, and with so few notes in the chord there is nowhere for the error to hide. A quick pass with a tuner before you play is the cheapest improvement you can make.

This page listens through the microphone and shows how far the string is from its target note in cents, a hundredth of a semitone. The needle moves left for flat and right for sharp. A line of text prompts you to raise or lower the string, and once the pitch lands inside a three-cent window around the target it changes to In tune. That window is tight enough that you will not hear a difference against another player or a backing track.

The buttons next to the needle sound each open string, so you can match by ear first and fine-tune with the display second. That is useful on a ukulele because the notes are fairly high and short, and hearing the target helps you know which peg to touch before you start turning.

The re-entrant G, explained

The standard ukulele tuning, G C E A, looks odd on paper. The strings do not rise steadily from the lowest to the highest. The fourth string, closest to your chin when you hold the instrument, is tuned to the G above middle C, which is higher than the C and the E beside it. This is called re-entrant tuning, because the pitch drops from the G to the C and then climbs again, which makes the instrument fold back on itself.

The result is the bright, bubbly sound people associate with the ukulele. Chords sit close together, because every note falls within a span of about an octave. Strumming gives a compact, shimmering cluster rather than the wide, deep spread of a guitar. A melody played across the strings can use notes in a natural run without the leap that a low string would add.

Some players prefer a linear arrangement and swap the high G for a G an octave lower, which is called low G tuning. The notes are G3 C4 E4 A4, so the strings climb in order. You gain a fuller bottom and a wider range for fingerstyle and solo playing, at the price of some of the classic chime. The table in the Numbers tab shows the frequencies for each layout, and the tuner has an entry for it, so just pick Low G and the string button for the fourth string plays the lower note.

If you move to low G, you need a wound or heavy fourth string. A thin nylon string tuned an octave down goes slack and buzzes, and the tuner will have trouble reading the weak vibration.

Soprano, concert, tenor and baritone

Ukuleles come in four common sizes. The soprano is the smallest and the traditional one, with a scale length around thirteen inches. The concert is slightly larger, around fifteen inches, and the tenor around seventeen. All three are normally tuned to G C E A, the same notes, so one tuning entry serves them. A bigger body gives more space between frets and often a warmer, rounder tone, but the open strings are the same pitches.

The baritone is the odd one out. At about nineteen inches it is tuned to D, G, B and E, the notes of a guitar's four thinnest strings. That is a fourth lower than the smaller sizes. Pick Baritone DGBE for it, because the other lists will send you to the wrong target. If you tune a baritone to GCEA by accident, the strings will be pulled far too tight and may break.

A useful consequence: a shape you finger on a baritone sounds a perfect fourth lower than the same shape on a concert ukulele. Players who also have a guitar like this because their chord knowledge from the top four strings transfers directly.

There is also a D tuning, A D F# B, which raises every string by a whole step. Some songbooks and school classes use it, and a few players like the brighter ring on a soprano. It puts more tension on the strings and body, so it suits a well built instrument and fresh strings.

Nylon strings and why they keep drifting

Nylon and fluorocarbon strings stretch much more than steel. A brand new set can lose its pitch every few minutes for the first couple of days. The pegs may also slip a little as the strings find their seating. If you notice that a string is flat each time you return to the tuner, that is stretching, not a fault in the tuner.

Speed things up by tuning to pitch, then lifting each string gently off the fingerboard, once along its length, and retuning. Repeat three or four times. Stretching in this way takes out most of the slack, and the strings settle within a day. Wound strings, such as a low G, hold their pitch more steadily once they have settled.

Temperature and humidity move the pitch too. A ukulele carried from a cold car into a warm room changes as the wood and strings adjust. Leave the instrument out of its case for several minutes before you tune, then check again after a short play.

Finish every string by tightening. When the display shows sharp, back the string off slightly past the note and wind it up again, since a string that arrives from underneath is far less likely to creep flat.

Ukulele tuning compared with guitar tuning

A guitar has six strings, and its lowest note sits nearly two octaves below the ukulele's lowest. The two are tuned differently, and a ukulele is not a small guitar, though the top four strings of a guitar match the baritone ukulele. A standard guitar spans from E2 to E4. A GCEA ukulele spans from C4 to A4, a much narrower register, which is why even a low G leaves the ukulele without a deep bass line.

Neighboring strings on a guitar move up in fourths with one major third. A concert ukulele moves a major third from C to E and a fourth from E to A, with the re-entrant G tucked in. The consequence is simple: chord shapes that you know from guitar will not carry over to GCEA, and the open chords that fit a ukulele (such as C with a single finger on the third fret of the A string) have little in common with guitar ones.

For a player coming from guitar, the guitar tuner on this site is the better match for six strings, and the ukulele tuner is the right one here. Both use the same detection method, so the readouts feel the same. The ukulele page simply swaps the lists, the buttons and the frequency targets.

Getting a clean reading on a quiet instrument

A ukulele is quiet. The strings are light, the body is small, and a phone microphone placed at arm's length may hear mostly the room. Hold the instrument close to the device, ideally with the sound hole pointing towards the microphone, and pluck at a moderate strength with your thumb. A very hard strike makes the pitch jump sharp for a moment, and a very soft one may not give the detector enough signal.

Close windows or turn off a fan if the needle jumps. The detector locks on to whichever pitch repeats most strongly, so a nearby voice or television can override your string. If the readout shows an unexpected note, such as an octave or fifth away from the target, let the string ring and listen again before turning the peg.

The small body also means the higher strings, like the A and the E, ring briefly. Pluck again if the display clears before the needle settles. For the high re-entrant G, a bright string sounds clear, but it can read slightly unsteady if the string is worn or dirty.

Is a tuner really necessary?

You can tune a ukulele by ear against a keyboard, a pitch pipe or the reference tones here. The common method uses the song My Dog Has Fleas, whose four notes happen to be G C E A. It gets a beginner close, but your ear can only judge a few cents in a quiet room and only if the first string is right. A tuner removes the guesswork and also teaches you what in tune looks like.

The most useful habit is checking before every session. Strings change daily, and a minute with the needle saves a chord progression from sounding off for the whole practice.

Where your sound goes

The microphone signal is processed in the page as you play and nothing is saved to disk or uploaded. Closing the tab releases the microphone. The page remembers only your selected tuning, so the next visit starts on the same ukulele.