How to read one of these boxes
Four vertical lines, one per string, in the order you look down at them: G C E A, with the G on the left. That G is the odd thing about a ukulele — it is tuned above the C beside it, not below it, which is why a strum sounds like a chord rather than like a bass note with a chord on top. The box does not care either way: it says which fret to hold, and a shape is the same shape whichever octave the string is in.
The thick line across the top is the nut. A dot is a finger, a bar across several strings is one finger laid flat over them, a circle above the nut means the string rings open and a cross means it is not played. The line of numbers under the box is the same shape written out — one cell per string, G to A, so 0003 is a C: three strings open and one finger on the third fret of the A string.
Why a ukulele chart is short and a guitar chart is not
Because there is hardly any choice to make. Four strings and a hand that reaches four frets leave very few fingerings that are even the right chord, and almost nowhere to hide a string you would rather not play. So the compact shape near the nut usually is the shape everybody plays, and a chart of one voicing per chord is not a simplification the way it would be on six strings.
These shapes are found rather than listed: every fingering inside the first twelve frets is tried, the ones that sound a note outside the chord or miss a note the chord needs are thrown away, and what is left is ranked — a string damped between two ringing ones costs the most, then leaving the first four frets, then dropping an outer string, then how far up the neck it sits. The shapes a ukulele book prints come out of that on their own: C as 0003, F as 2010, G as 0232, Am as 2000, B7 as 2322. Nobody typed them in.
The chords four strings cannot hold
A minor ninth is five notes and keeps four of them once the fifth is dropped — four different notes, on an instrument with exactly four strings to put them on. For most roots that works out; for at least one it does not, and there is no honest picture to draw. Those cards say so and list the notes instead of showing a shape that would be quietly wrong: Abm9.
The hard chords are not the guitar’s hard chords
Worth knowing if you play both, because the instinct transfers wrongly. E is a stretch on a guitar and three easy fingers on a ukulele. Bb is a first-fret barre here and a comfortable shape there. C is one finger on a ukulele and three on a guitar. So a key that sits badly on one instrument may sit perfectly on the other — and if it sits badly on the one in your hands, the capo calculator knows which fret fixes it, ukulele included.
The guitar shapes for all the same chords are on their own chart, or use the switch at the top of this one.
What the app adds
This page knows every chord and nothing about your songs. Strumfolio puts the same shapes inside the sheet you are playing from: the instrument is a setting, so the whole songbook draws ukulele shapes, a chord is a tap away from its fingering with its alternatives behind it, and the shape you pick is remembered for that chord in that song on every device you sign in on — offline included.
If your sheets are still text files, the ChordPro converter is the way in, and it costs nothing either.