Online guitar tuner

How to tune a guitar with this tuner

1. Press Start and allow microphone access when your browser asks. The sound is analyzed on your device and is never recorded or uploaded.
2. Hold the guitar close to the microphone of your phone or computer and switch off fans, televisions and other music in the room.
3. Pick the low E string (string 6) once with a medium stroke and let it ring. With Detect String on, the tuner recognizes which string you played.
4. If the reading is flat, tighten the peg slowly. If it is sharp, loosen the string a little below the note and then tighten it back up to the note, because a string tuned upward holds its pitch better.
5. Stop turning when the string stays within ±2 cents for a moment. The tuner then marks it as in tune.
6. Tune the A, D, G and B strings and the high E string (string 1) the same way, then play every string once more in the final recheck. Changing the tension of one string moves the others slightly.

Standard guitar tuning notes and frequencies

Standard tuning from string 6 to string 1 is E2 A2 D3 G3 B3 E4. The table lists the note and target frequency of each string at the A4 reference currently selected.

Auto mode and By Ear mode

In Auto mode the tuner listens through the microphone and shows the nearest string, the note and how many cents sharp or flat you are. One cent is one hundredth of a semitone, so a reading of +20 means the string is a fifth of a semitone too high.

In By Ear mode the tuner plays the target note for each string as a plucked-string sound or a pure sine tone. Turn on Loop Note to repeat the reference every 2 seconds, adjustable from 1 to 5 seconds, so both of your hands stay on the guitar. Match the string to the reference until the slow wobble between the two sounds disappears. The guide on how to tune by ear explains how to listen for that wobble.

Press B or A on a keyboard to switch modes, Space to start or stop listening, the number keys to pick a string and L to turn the loop on or off.

When to turn Detect String off

With Detect String on, you can play any string and the tuner compares it with the nearest string of the tuning. This is the fastest way to touch up a guitar that is already close to pitch.

A string that is far from pitch can sound closer to its neighbor than to its own note, and the tuner will then compare it with the wrong string. This happens with new strings and when you change tuning. Turn Detect String off and tap the peg of the string you are tuning. The reading then stays on that string however far away it is and tells you what to do, for example "Tune up 2 semitones".

Standard tuning and other instruments

In standard tuning each string is five frets (a fourth) above the string below it, except the B string, which is four frets (a major third) above the G string. That one exception is why the B string is the one most beginners tune wrong when they tune by fretting the string below.

The tuner opens on an acoustic guitar in standard tuning. Use the instrument buttons above the tuner to switch to the electric guitar, bass, ukulele, chromatic or custom tuner, and use the tuning menu for drop, open and lowered tunings. The guitar tunings page explains each family of tunings.

Privacy and offline use

The audio from your microphone is analyzed in your browser and is never recorded or uploaded. There is no account and no sign-up.

You can install the tuner from your browser menu so it opens like an app. After the first visit it works offline, which helps in rehearsal rooms and venues with no signal. The screen stays awake while the tuner is listening, and Stage mode shows a full-screen, oversized readout that you can read from a few steps away.