Free Online Guitar Tuner

How the online tuner works

When you click Start Tuning, your browser asks for microphone permission (you can deny it to anyone else on the web — we never transmit your audio). The tuner runs an autocorrelation pitch detection algorithm on the incoming signal, identifies the fundamental frequency, and compares it to the nearest target pitch in the selected tuning.

The needle swings in real time. Green glow = in tune (within ±3 cents). Amber = close. Red = significantly sharp or flat. Flat note? Your string is tuned too low — tighten the tuning peg. Sharp? Loosen it.

Tunings supported

Standard (E A D G B E), Drop D, Drop C, Drop B, Half Step Down (Eb Ab Db Gb Bb Eb), Whole Step Down (D G C F A D), Open D, Open G, Open E, Open C, DADGAD, Double Drop D, plus any fully custom tuning.

Bass: 4-string (E A D G), 5-string (B E A D G), 6-string (B E A D G C). Ukulele: standard GCEA and baritone DGBE.

Reference pitch: 432 Hz, 440 Hz, or custom

440 Hz is the international standard since 1955. Some players prefer 432 Hz for a slightly warmer sound (claimed to feel more "natural," though the acoustic difference is debated). The reference is adjustable in the settings panel — every target frequency rescales automatically.

Why a chromatic tuner beats a guitar-only tuner

A chromatic tuner detects any pitch, not just E A D G B E. That means it works for alternate tunings, bass, ukulele, mandolin, banjo, violin, and even voice. You don't have to pre-select a string — just play the note and the tuner identifies it.