Free Online 7-String Guitar Tuner
Seven targets, one low B, each string read against its own note.
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Left to right: 7th 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. Play one open string at a time, and the tuner shows how sharp or flat you are from that string’s target in cents. Tap a string button to hear the note and lock the tuner to it.
The bar spans −50 to +50 cents. Zero is perfectly in tune. On the low B, read the settled part of the history line: a hard pick stroke is genuinely sharp for the first few cycles, and a low string takes longer to settle than a high one.
The tuner reads against the nearest open string of 7-string standard tuning (B1, E2, A2, D3, G3, B3, E4), 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.
Guitar is already selected and no transposition is applied: guitar is written an octave above where it sounds, and the tuner shows the sounding octave. Changing the dropdown to another instrument turns string mode off; tapping a string turns it back on.
Default is A440. Tap + / − to match a recording or another instrument that cannot be adjusted.
Standard 7-string tuning is B1, E2, A2, D3, G3, B3, E4: a normal six-string guitar plus a seventh string a perfect fourth below the low E. The low B sounds at 61.74 Hz, only a little above the B on a 5-string bass, and every chord shape from the six-string carries across unchanged with the extra string adding a fourth below. This page reads each of the seven strings against its own target, with the buttons in low-to-high order so the leftmost is the B.
Low strings are hard for a microphone tuner for a physical reason: the fundamental of a low B is weak compared with its harmonics, and a tuner can lock onto the octave, B2, and report the string as in tune when it is not. Two things fix this. Pluck the string over the neck pickup or the end of the fingerboard rather than at the bridge, which favours the fundamental; and read the settled plateau on the history line rather than the first instant. If the note display briefly shows the string as a different octave and then drops to B1, that is the tuner finding the fundamental as the attack fades, and it is the B1 reading you want. Tapping the B1 button locks the tuner to that target so a passing harmonic cannot pull the reading to another string.
String gauge is the other half of getting a low B to read cleanly. A .054 seventh string at B1 on a 25.5 inch scale is slack and reads unsteady; .059 to .062 is more typical, and 7-strings built for lower tunings often have 26.5 or 27 inch scales for this reason. A string that wobbles in pitch on the tuner even after it settles is usually a string too light for the tension, or an intonation problem at the bridge: compare the twelfth-fret harmonic with the fretted twelfth-fret note and adjust the saddle if they disagree.
Most 7-string players who tune down do so uniformly, a half step to B♭ standard or a whole step to A standard, or use drop A, which lowers only the seventh string from B to A. For a uniform drop, use the chromatic tuner; for drop A, tune to this page and then take the seventh string down a whole step, which is the same move as drop D one string lower. 8-string players add an F♯1 below the B and will find the 5-string bass page, whose lowest target is B0, useful for the range.
Frequently asked questions
What is standard tuning on a 7-string guitar?
B1, E2, A2, D3, G3, B3, E4 from the lowest string to the highest. It is a normal six-string tuning with a seventh string added a perfect fourth below the low E.
Why does the tuner read my low B as the wrong octave?
The fundamental of a low B is weak and its octave harmonic is strong, so a tuner can briefly lock onto B2. Pluck over the neck, let the note settle, and read the plateau on the history line. Tapping the B1 button locks the tuner to that target.
What is drop A on a 7-string?
Drop A lowers only the seventh string a whole step, from B1 to A1, leaving the other six in standard. It is the 7-string equivalent of drop D. Tune to this page first, then lower the seventh string a whole step.
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