// analyze · tool 27
Instrument Tuner
A chromatic tuner with a real needle: sub-cent autocorrelation pitch detection from your microphone, with the A4 reference adjustable from 432 to 446 Hz.
waiting for microphone
Tune any instrument with your microphone
This is a chromatic tuner — it hears any note, names the nearest pitch, and shows exactly how many cents sharp or flat you are on a damped needle. It works for guitar, bass, ukulele, violin, cello, brass, woodwinds, piano and voice. Behind the needle is an autocorrelation pitch detector with parabolic interpolation, the same algorithm family used in hardware tuners, resolving well below one cent on a clean note.
How to get a stable reading
- Play one note at a time and let it ring — chords confuse any pitch detector.
- Get reasonably close to the mic and minimize background noise.
- Aim for the needle centered: within ±5 cents is in tune to almost every ear.
- On guitar, tune up to pitch — approaching from below keeps the string stable.
Adjustable reference pitch
Most music tunes A4 to 440 Hz, but that's a convention, not physics: many European orchestras sit at 442–443 Hz, period ensembles go lower, and the 432 Hz crowd prefers 8 Hz down. Set the reference between 432 and 446 Hz and every note name shifts accordingly.
FAQ
How accurate is this tuner?
Sub-cent on a clean sustained note — more precise than audible. Real-world accuracy depends on your mic and room noise.
Is my microphone audio recorded or sent anywhere?
No — it's analyzed in real time in your browser and immediately discarded.
What does the cents display mean?
A cent is 1/100 of a semitone. Within ±5 cents of center reads as in tune to almost all listeners.
Why can I change the A4 reference?
Orchestras and traditions differ: 440 is standard, 442–443 common in Europe, 432 preferred by some. All note names shift with the reference.