Guitar Tuner

This guitar tuner listens through your device's microphone and works out the pitch of the string you play. It shows the note name, the frequency in hertz and how far you are from the target string in cents (a cent is one hundredth of a semitone). Pick standard tuning, drop D, half step down, 4-string bass or ukulele, and change the reference pitch if your band tunes to something other than A4 = 440 Hz. The sound is analysed on your device only – nothing is recorded or uploaded. If you prefer to tune by ear, tap any string button to hear its reference tone.

In standard tuning the six strings, from the thickest to the thinnest, are E2 (82.41 Hz), A2 (110.00 Hz), D3 (146.83 Hz), G3 (196.00 Hz), B3 (246.94 Hz) and E4 (329.63 Hz), based on A4 = 440 Hz. Drop D lowers only the low E string to D2 (73.42 Hz). The string buttons under the tuner show the exact target frequency for the tuning you pick.

Tune in a quiet room and play one string at a time. Pluck firmly, then let the note ring rather than muting it straight away. Hold the phone or laptop close to the guitar's sound hole or the amp speaker. If the tuner jumps between notes, it may be hearing an overtone – pluck a little softer, closer to the neck. Always tune up to the note: if a string is sharp, go below the note first and then bring it up, which helps the string stay in tune.

Choose Bass – 4 string for E1 A1 D2 G2, or Ukulele – GCEA for the common re-entrant ukulele tuning (G4 C4 E4 A4). Low bass notes are harder for small phone microphones to pick up; if the reading is unstable, play the string a little harder or tune the 12th-fret harmonic, which sounds one octave higher.