Tuner

What it's for

Tune an instrument or check your singing against the right note, with nothing to install. It listens through your microphone, finds the pitch of what it hears, and shows the nearest note and how far off it is in cents (hundredths of a semitone).

For example, when your guitar has gone out of tune before a practice, play each open string in turn and turn the peg until the needle sits in the middle and turns to the accent colour.

How to use it

Press Start listening and allow the microphone when the browser asks. Play or sing one note at a time: the big letter is the nearest note with its octave (E2 is a guitar’s low E string), and the line below gives the frequency and whether it’s sharp (too high) or flat (too low). The needle moves right when sharp and left when flat, and is coloured once it’s within 5 cents. Screen readers hear the note when it changes.

Concert pitch sets the A above middle C (A4), normally 440 Hz; some orchestras use 442 and some players 432. It’s remembered in this browser.

Example

Open the Tone Generator on another device, set the frequency to A4 and play it near the microphone. The tuner shows A4, 440.0 Hz · in tune, with the needle in the middle. Change Concert pitch to 442 and it reads 8 cents flat.

Good to know

It reads one note at a time: a strummed chord or a noisy room gives an unsteady reading or none. It hears from about 40 Hz (a bass guitar’s low E) to 2,000 Hz; very low notes on a laptop microphone can read an octave high. The sound is only analysed on this page and never recorded or sent anywhere.