ABOUT THE WORKBENCH

A clear note.
An honest reading.

Drop Tuner is a small tool for tuning a six-string guitar to Drop C or Drop D. Select a string, play a clean note and adjust its pitch against a fixed target.

How the reading works

Targets use twelve-tone equal temperament with A4 at 440 Hz. Frequency is calculated as 440 × 2^{(MIDI note − 69) / 12}. The cents difference is 1200 × log₂(detected frequency / target frequency).

Pitch detection uses Pitchy. Analysis removes DC offset, reduces high-frequency noise and rejects readings when the waveform suggests an octave ambiguity. The display filters short-term variation and waits for a steady pitch within ±3 cents before offering confirmation. The tool never automatically divides or multiplies an octave to mark a note in tune.

Beta testing and limits

Generated digital signals, selected public guitar-library recordings and the tuning-state logic have been tested locally. Desktop Chromium and Safari have also been checked with synthetic audio input. Library recordings are edited samples, not calibrated pitch references. These tests do not establish the accuracy of a real microphone, guitar or mobile browser. Real-instrument checks and iOS/Android validation remain outstanding. The ±3-cent window is a confirmation threshold, not an accuracy guarantee.

Use one sustained, clean string at a time. Chords, distortion, background hum, strong harmonics and device audio processing can confuse detection. If the fundamental and odd harmonics are absent, a waveform can be indistinguishable from a note one octave higher; this tool cannot always resolve that ambiguity. If a reading is unexpected, stop and check the selected string before turning a peg further.

Your microphone and privacy

Microphone access begins only when you press Enable microphone and your browser grants permission. Audio samples are processed in memory on your device. This app does not record audio, upload it, create accounts, set tracking cookies or run analytics. The hosting provider may receive ordinary page requests.

Stop microphone releases the input. Audio also stops when the page is hidden or you leave it. Reference playback turns off input to prevent feedback. See MDN’s microphone permission documentation for browser requirements.

Reference notes

Note layouts were cross-checked against Gibson’s Drop C guide and Drop D guide. Frequencies here are calculated from the formula above, not copied measurements.

Last substantive update: October 25, 2026. This project is not affiliated with the referenced services.