Tune-o-matic, a browser tuner that also explains intonation

Field notes

The application separates two jobs: identifying pitch while tuning, then diagnosing fret-placement error by comparing a 12th-fret harmonic with the corresponding fretted note. Its interface covers 4-, 6-, 7-, and 12-string setups, drop and open tunings, and A4 references from 432 to 440Hz. It also exposes detection sensitivity and cent-based tolerances, with settings stored in the browser. The tutorial can be viewed without granting microphone access.