Tuner

Tune an instrument using a single sustained note. The microphone is used only after Start and browser permission; audio is never uploaded or saved. Reference A4 is adjustable from 400 to 480 Hz. Notes use international spelling (B is German H). 100 cents equal a semitone; the center and ±5 cents indicate in tune. Higher/lower indicates the correction to make. YIN-based detection measures approximately periodic tones from about 25 to 2000 Hz, including low bass strings; chords, strong background noise, attacks or a weak fundamental may produce no result or a wrong octave. Stop, changing tools or hiding the page ends microphone access. Only the reference is stored as a preference.

The reference updates immediately while listening. Enter in the field never starts the microphone. Only this raw input is retained, including unfinished or invalid drafts; audio, detected notes and meter readings are temporary. The meter has a bounded width for easy reading on large screens.