Free online ukulele tuner

A ukulele drifts out of tune more than most instruments. Nylon and fluorocarbon strings stretch, the small pegs slip, and temperature changes move all four strings at once. A tuner that listens through the microphone fixes that in a minute, and knowing what it is telling you makes the minute shorter. Below is what the four strings should read, how this tuner decides which string you are playing, how to tune low G and baritone, and what to check when a ukulele won’t stay in tune.

Standard ukulele tuning: G C E A

Soprano, concert and tenor ukuleles share one tuning. From the fourth string, the one nearest your chin, to the first: G4, C4, E4 and A4. The frequencies at the standard reference pitch, A = 440 Hz, are 392.00, 261.63, 329.63 and 440.00 Hz. Middle C on a piano is the same note as the ukulele’s third string.

The fourth string breaks the pattern. Instead of being the lowest note, the G sits above the C, between the E and the A in pitch. This re-entrant tuning keeps all four strings inside a narrow range, which gives strummed chords their bright, close sound and lets melodies move across strings in small steps. It also explains a common surprise: the C string, not the G, is the lowest note on a standard ukulele.

How the tuner reads a string

When you pluck a string, the tuner measures its pitch many times a second and shows the result in cents. A cent is a hundredth of a semitone, so a reading of +20 means the string is a fifth of a semitone sharp, and −50 means it is a quarter tone flat. Most people stop hearing an error somewhere around 5 cents, and the tuner treats a string as in tune when it holds within a few cents for a second.

In Auto mode the tuner compares the pitch with all four strings of the preset and picks the nearest. That works once the strings are roughly right. On a ukulele that is far out, a badly flat A can look nearer to the E, and the tuner will happily tune your first string to the wrong note. If that happens, tap the string’s button below the gauge. The tuner switches to Manual and measures everything against that one string until you tap it again.

Tuning step by step

1. Hold the ukulele as you play it, so the strings settle at playing tension, and keep the room quiet.
2. Start with the fourth string, G. Pluck it once and let it ring while you watch the reading.
3. If the reading is flat, tighten the peg a little. If it is sharp, loosen it past the note and come back up, which helps it hold.
4. Repeat for the C, E and A strings.
5. Go round all four once more, since tightening one string pulls slightly on the neck and moves the others.
6. Strum a C chord (0-0-0-3). It should sound clean, with no single string sour against the rest.

Low G tuning

Low G keeps the same four note names but fits a thicker fourth string tuned an octave lower, to G3 at 196.00 Hz. The ukulele gains a bass note and five more notes at the bottom of its range, so fingerstyle arrangements and jazz chords sound fuller. Chord shapes and names stay the same. Choose Low G in the Tuning menu so the tuner aims the fourth string at G3; in standard mode it would try to pull a low-G string up an octave. A standard G string cannot be tuned down that far without going slack, so low G always means a string made for it.

Baritone ukulele tuning

The baritone is the largest ukulele and the odd one out. It is tuned D3, G3, B3 and E4 from the fourth string to the first, the same notes as the four highest strings of a guitar, and it has no re-entrant string. Pick Baritone in the Tuning menu. Chord charts written for a C-tuned ukulele still work as shapes, but every chord sounds a fourth lower: the shape that makes C on a soprano makes G on a baritone.

Tuning by ear, without a tuner

A ukulele can also be tuned to itself, string against string. Get one string right first, usually the A, from a piano, a tuning fork or a steady reference note such as the A tuning drone. Then press the E string at the fifth fret and match it to the open A. Press the C string at the fourth fret to match the open E, and the G string at the second fret to match the open A. When two notes are close but not equal you hear a slow wobble in the sound; turn the peg until it stops. The guide to how to tune a ukulele covers this method, the pegs and alternate tunings in more detail.

When a ukulele won’t stay in tune

• New strings. Nylon and fluorocarbon stretch for several days. Tune up, pull each string gently away from the fretboard along its length, and retune until it holds.
• Slipping pegs. Friction pegs on cheaper ukuleles have a small screw at the end; a quarter turn tighter stops them creeping back.
• Temperature and humidity. A ukulele carried in from the cold reads flat and drifts as it warms up. Let it sit for ten minutes before tuning.
• Chords sound wrong although every string reads right. Check the octave. A G string tuned to G3 instead of G4 reads as G, yet sounds wrong in chords; compare it with the table above.

After tuning

Once the four strings are in tune, the first chords are C, Am, F and G7, and the guide to ukulele for beginners takes you through them. The list of ukulele songs for beginners has the first songs to play on them, each linked to its sheet music on MuseScore.