Guitar and Ukulele Tuner
Tune guitar, ukulele, bass, violin, and mandolin with live microphone pitch detection.
🔒 Processed entirely in your browser — nothing you enter here is ever uploaded.
Result
About this tool
Choose an instrument, allow the microphone, and play one string. The page opens an AnalyserNode with an FFT size of 4096 and reads the time-domain buffer. Pitch comes from autocorrelation, not from the loudest FFT bin. Frames whose RMS is below 0.012 are ignored. The search looks for a repeat between about 40 Hz and 1000 Hz, and it keeps a pitch only when the best correlation is above 0.85. The large note name is the nearest chromatic pitch from that frequency. The cents are measured against the nearest string in the preset you selected, using 1200 times the base-2 log of heard frequency over target frequency.
Ukulele, the tuning most often searched for on this page, is re-entrant high G: G4 at 392.00 Hz, C4 at 261.63 Hz, E4 at 329.63 Hz, and A4 at 440.00 Hz. Guitar is E2 82.41, A2 110.00, D3 146.83, G3 196.00, B3 246.94, E4 329.63. Bass is E1 41.20, A1 55.00, D2 73.42, G2 98.00. Violin and mandolin share G3 196.00, D4 293.66, A4 440.00, and E5 659.25. Those Hertz values are the standard A4 = 440 Hz set. There is no slider for 432 Hz or any other reference.
The needle does not jump to every raw frame. It eases toward the new offset, and it snaps only on the first reading or after the meter has gone stale. In tune means the smoothed offset is within 4 cents. If autocorrelation finds nothing confident for 550 milliseconds, the last reading is faded instead of being left looking live. Tune one string at a time. A second note, a noisy room, or a string quieter than the RMS gate leaves the needle without a new pitch. The page does not name a song key or a chord.
Example. A steady 440 Hz tone on the ukulele preset is labeled A4 and counted as in tune when the smoothed offset from that string is within 4 cents.
Limit. String frequencies are the standard A4 = 440 Hz set, with no calibration slider. Pitch search covers about 40 Hz to 1000 Hz, and a reading older than 550 ms is marked stale.
How do I tune a ukulele online?
Choose Ukulele and allow the microphone. The four targets are G4 at 392.00 Hz, C4 at 261.63 Hz, E4 at 329.63 Hz, and A4 at 440.00 Hz, which is re-entrant high-G tuning. Play one string. The note name is the nearest chromatic pitch, and the cents are measured against the nearest of those four strings.
What does in tune mean on the meter?
The raw offset is 1200 × log2(heard frequency / target frequency). The needle eases toward that number, and the highlight turns on when the smoothed offset is within 4 cents, flat or sharp. A frame with no confident pitch for 550 ms fades the last reading instead of snapping back to zero.
Can I tune a guitar, bass, violin, or mandolin, or set A to 432?
Guitar is E2 82.41, A2 110.00, D3 146.83, G3 196.00, B3 246.94, E4 329.63. Bass is E1 41.20, A1 55.00, D2 73.42, G2 98.00. Violin and mandolin share G3 196.00, D4 293.66, A4 440.00, E5 659.25. Those Hertz values are fixed. There is no 432 Hz reference control.