Accordo — Free Online Guitar & Bass Tuner
Accordo is a free, accurate chromatic tuner for 6, 7 and 8-string guitars and 4, 5 and 6-string basses.
It offers more than 50 tunings (Standard, Drop D, Drop C, Drop B, Open G, Open D, DADGAD, All Fourths…),
a flat switch, reference tones to tune by ear, and automatic string detection — with no ads and no tracking.
JavaScript is required to use the tuner.