Tune first. Trust the reading.

TuneToy is a free instrument tuner designed around a simple promise: identify the string you intend to tune, measure it accurately, and keep the microphone signal on your device.

Why TuneToy exists

A basic chromatic tuner reports the nearest musical note. That is useful for identifying arbitrary pitches, but it can be misleading when a guitar string is badly flat: the wrong note may appear nearly centered. TuneToy's instrument modes compare the sound with the strings in the selected tuning instead. The display keeps guiding you toward the intended string, and a manual string lock is available when a string starts far away.

How accuracy is checked

The pitch detector uses the YIN method and is exercised against pure tones, harmonically rich plucked-string models, noise, and missing-fundamental signals that can cause simpler detectors to jump an octave. The current automated battery measures worst-case synthetic error below one tenth of a cent. In everyday use, microphone quality, background noise, string attack, and instrument setup matter far more than the detector's numerical limit.

Privacy is part of the architecture

Microphone access begins only after you press Start tuning. The browser supplies short audio buffers directly to the pitch detector; TuneToy does not record, upload, transmit, or store them. There is no account system or database of tuning activity.

Built to remain a small, useful tool

TuneToy is an independent web utility rather than an app-install funnel or lesson subscription. Its focus is deliberately narrow: fast access, clear guidance, alternate tunings, and dependable behavior on the device already in your hand.