Free Online 4-String Banjo Tuner
Four strings in fifths, no drone. Each read against its target.
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Left to right: 4th 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. Banjo strings decay fast, so pluck cleanly and read the value once the history line flattens rather than the attack.
The tuner reads against the nearest open string of Tenor CGDA tuning (C3, G3, D4, A4), 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.
Banjo is already selected and no transposition is applied: the note names shown are the sounding notes. Changing the dropdown 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 tenor banjo tuning is C3, G3, D4, A4, four strings in perfect fifths, the same pitches as a viola and one fifth below a mandolin. There is no short drone string. The tenor banjo came out of the 1920s dance bands and Dixieland, where it was strummed with a plectrum for rhythm, and CGDA is still what jazz and trad-jazz players use. The buttons above the display show the four targets from low to high, and the tuner reads each string against its own.
Irish traditional players tune the tenor banjo differently: GDAE, an octave below a mandolin or fiddle, with the same fiddle fingering for the tunes. That is G2, D3, A3, E4, and it needs heavier strings than CGDA; a set made for one tuning does not work well in the other. This page is set for CGDA. For Irish tuning, tap the buttons for reference and use the chromatic tuner for the targets, or tune the G2 an octave below the G3 button, the D3 a fifth above it, and so on. The plectrum banjo, the other common four-string, has a longer neck and is usually tuned CGBD, like a 5-string without the drone, which the chromatic page also handles.
Banjo strings are light and the head makes the notes loud and short, so give the tuner a clean, moderate pluck and read the settled value on the history line. The head is also the first place to look if all four strings read unsteady or drift the same direction from day to day: a loose or humidity-softened head lowers the pitch and dulls the fundamental. The A4 string is the thinnest and the one that breaks while tuning; approach it from below in small moves and stop at zero.
A tenor banjo in a session or a band tunes to A440 like everything else. Check intonation after tuning by comparing the twelfth-fret harmonic with the fretted twelfth-fret note on each string; the movable bridge on a banjo shifts easily, and if the harmonic and the fretted note disagree, the bridge has moved and needs to be slid forward or back, not the strings retuned. For a 5-string in open G, use the banjo tuner; for the mandolin, tuned a fifth above this page, the mandolin tuner.
Frequently asked questions
How is a 4-string banjo tuned?
A tenor banjo is tuned C3, G3, D4, A4 in fifths, the same as a viola. Irish players use GDAE (G2, D3, A3, E4), an octave below a mandolin. A plectrum banjo is usually CGBD. This page is set for CGDA.
What is the difference between a tenor and a plectrum banjo?
Scale length and tuning. A tenor has a shorter neck (17 or 19 frets) and is tuned in fifths, CGDA or GDAE. A plectrum has a long 22-fret neck and is tuned CGBD, like a 5-string banjo without the drone string.
Why do all my strings read unsteady?
Usually the head. A loose or humidity-softened banjo head lowers the pitch and weakens the fundamental, so every string drifts the same way. Tighten the head evenly, retune, and check the bridge has not slipped.
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