Guitar Tuner

From the thickest string (closest to your face) to the thinnest, the standard 6-string guitar is tuned to E2 (82.41 Hz), A2 (110 Hz), D3 (146.83 Hz), G3 (196 Hz), B3 (246.94 Hz), and E4 (329.63 Hz). The reference pitch most modern tuners and recordings use is A4 = 440 Hz, which is why your A string sits exactly an octave plus an octave below that frequency. The mnemonic 'Eddie Ate Dynamite Good Bye Eddie' helps beginners remember the order.

The tool plays each string in turn so you can match by ear. Each note uses five summed sine wave harmonics (fundamental plus 2nd, 3rd, 4th and 5th overtones with decreasing gain) to imitate the timbre of a real plucked string, rather than a sterile single sine wave. Pluck your string, listen to the reference, and turn the machine head slowly until the two pitches lock into a single tone with no audible 'wobble'. The wobble (called beating) is what your ear hears when two close-but-not-identical frequencies interfere; tune until it disappears.

The tool ships with 11 tunings beyond standard. Drop D (D-A-D-G-B-E) lowers only the 6th string by a tone, giving you a power-chord-friendly low D for rock, metal, and a fair amount of folk. Drop C and Drop B keep going down for heavier styles. Half-step-down (Eb tuning) lowers everything by a semitone for a fuller, looser feel popular with Hendrix, Stevie Ray Vaughan and many country players. Open tunings (Open D, Open G, Open E) tune the strings to a chord shape, so strumming the open strings produces a major chord; these are the foundation of slide guitar and a lot of acoustic blues.

DADGAD is worth singling out. Dropping the 6th to D, the 2nd to A and the 1st to D gives you a sus4 chord on the open strings, which is why Celtic and modern fingerstyle players love it; it sits ambiguously between major and minor and rings out spectacularly. Open G (D-G-D-G-B-D) is Keith Richards's tuning of choice and behaves differently again. Switching tunings every few practice sessions builds your ear for note relationships, since you cannot just rely on muscle memory. The [chord library](/chord-library) only covers standard tuning, so once you switch to DADGAD you will need a separate chord reference.

This tool is a reference-pitch tuner: you hear the correct note and turn the peg until your string matches. That trains your ear over time and works in any environment, including with broken or muffled microphones. The trade-off is that you need to be able to hear small pitch differences, and a noisy room makes it harder. Beginners typically take 30 seconds per string for the first few months and a few seconds per string after that.

Microphone-based tuners (which use the Web Audio API to listen and detect pitch) are faster but rely on your phone or laptop microphone hearing the string clearly. They struggle in band rehearsals, outside, or when other instruments are sounding. They also do nothing for ear training; you watch the needle and never learn to hear the pitch yourself. The middle ground is to use ear tuning for a few weeks until your ear locks the pitches in, then switch to microphone tuning for speed when needed. New strings drift out of tune for the first few hours of playing as they stretch, so retune every 10 minutes or so during a fresh string-change session. The [bass tuner](/bass-tuner) and [ukulele tuner](/ukulele-tuner) work the same way for those instruments.