Mandolin tuner: G D A E, free, with your mic

This is a free online mandolin tuner that listens through your microphone. It opens on standard mandolin tuning, G D A E. Press Start, play one string of a pair with the other muted, let the note settle, then aim for 0 cents. Then do the same for its twin. No account, no download. It sits alongside the rest of our free guitar tools.

Standard mandolin tuning: G D A E

A mandolin is tuned G D A E, from the lowest pair of strings to the highest. Those are the same four notes as a violin, and like a violin the strings rise in fifths: each one is seven half steps above the last. That even spacing is what makes melodies and fast runs lie so well under the fingers.

The eight strings are four pairs, called courses. The two strings of a course are tuned to exactly the same pitch and played together, as if they were one string. So you have eight strings to tune and only four target notes, which is why the tuner shows four, not eight.

The reference pitch menu, next to the tuning menu, offers A at 432, 440 and 442 Hz. It opens on 440, which is what the frequencies above assume. Change it only if you are tuning to another instrument or a recording that sits elsewhere.

How to tune a mandolin, pair by pair

The method is the same for all four courses: one string at a time, with its twin silenced, then the pair together as a check.

1. Press Start and allow the microphone. Nothing is recorded or uploaded: the signal is analyzed in your browser and discarded.
2. Lay a fingertip lightly on one string of the G pair to mute it, and pick the other. It should read G. Two strings sounding at slightly different pitches give the tuner a blurred note, which is why you mute one.
3. Wait for the reading to settle, then look at the cents. Flat means too low, so tighten. Sharp means too high, so loosen. Turn the peg in small steps, especially on the E pair, where the pitch moves fastest.
4. Swap: mute the string you just tuned, pick its twin, and bring it to the same 0 cents.
5. Play the pair together. A slow wobble in the sound, a beating, means the two strings are still slightly apart. Nudge one until it disappears.
6. Repeat for D, A and then E. Finish with a second pass over all four courses: eight strings pulling on a small instrument shift each other a little.

If a string has gone far out of tune, open Settings and tick Open string sound. One button per course appears. Tap one and you hear its reference pitch, and the tuner then measures against that course even when the string is several half steps away.

The ear check, for when you have no tuner at hand. Because the courses are a fifth apart, the seventh fret does the work: the G pair at the seventh fret matches the open D, the D pair at the seventh fret matches the open A, and the A pair at the seventh fret matches the open E.

First mandolin chords

Once the mandolin is in tune, these first position shapes are the ones you will meet first. The numbers are frets, G pair first, 0 for an open pair. Each finger holds down both strings of a course. Because the mandolin is tuned in fifths, none of these are guitar shapes.

If a chord sounds wrong while the fingering is right, check the pairs before you blame your left hand. One string slightly off inside a course makes every chord that uses it sound sour.

Tremolo, the fast back and forth of the pick that sustains a note, is where a mistuned pair shows most: the two strings beat against each other and the note sounds nervous instead of singing. Work it slowly against the online metronome, and speed up only once it stays even.

Mandola, octave mandolin and other relatives

Only the mandolin has its own preset. Its larger relatives are tuned just as accurately, because the reading is chromatic: the tuner names the nearest note to whatever you play and shows how far off it is in cents. Keep the mandolin preset loaded for them, for a reason worth knowing.

When a string is less than a whole step from one of the preset's strings, the tuner assumes you are aiming for that string and measures against it. With the mandolin preset, every note below is either a mandolin course or far from all of them, so the reading always lands on the right note.

• Mandola. Larger than a mandolin and tuned a fifth lower, C G D A, for a warmer, darker sound.
• Octave mandolin. The mandolin's G D A E, one octave down, on a longer neck.
• Banjo-mandolin. A banjo body with a mandolin neck, eight strings in four pairs, tuned G D A E like a mandolin. Use this page as it is.
• Tenor banjo. Four single strings, in C G D A or, for Irish music, G D A E an octave below the mandolin. The banjo tuner page covers both, and the 5 string banjo.

Coming from a guitar? The online guitar tuner opens on standard tuning, and how to tune a guitar explains cents, flat and sharp from the start. The method is the same on four pairs as on six strings.