Online guitar tuner

Play a string and the tuner recognises which one it is, tells you whether it is flat or sharp, and turns green once it is in tune. Free, in your browser, nothing to install.

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± 0 ¢— Hz

Tap “Turn on microphone” and play a note.

Instrument Tuning A = Hz

Sound is analysed on your device. Nothing is recorded or sent anywhere.

Notes and frequencies for each tuning

Standard tuning for guitar is Standard (EADGBE): E2 A2 D3 G3 B3 E4, from string 6 to string 1. These are the exact frequencies with A at 440 Hz; change the reference in the tuner and they are recalculated.

Standard (EADGBE)

String	Note	Frequency (A = 440 Hz)
6	E2	82.41 Hz
5	A2	110.00 Hz
4	D3	146.83 Hz
3	G3	196.00 Hz
2	B3	246.94 Hz
1	E4	329.63 Hz

Drop D

String	Note	Frequency (A = 440 Hz)
6	D2	73.42 Hz
5	A2	110.00 Hz
4	D3	146.83 Hz
3	G3	196.00 Hz
2	B3	246.94 Hz
1	E4	329.63 Hz

DADGAD

String	Note	Frequency (A = 440 Hz)
6	D2	73.42 Hz
5	A2	110.00 Hz
4	D3	146.83 Hz
3	G3	196.00 Hz
2	A3	220.00 Hz
1	D4	293.66 Hz

Open G

String	Note	Frequency (A = 440 Hz)
6	D2	73.42 Hz
5	G2	98.00 Hz
4	D3	146.83 Hz
3	G3	196.00 Hz
2	B3	246.94 Hz
1	D4	293.66 Hz

Open D

String	Note	Frequency (A = 440 Hz)
6	D2	73.42 Hz
5	A2	110.00 Hz
4	D3	146.83 Hz
3	F#3	185.00 Hz
2	A3	220.00 Hz
1	D4	293.66 Hz

Open E

String	Note	Frequency (A = 440 Hz)
6	E2	82.41 Hz
5	B2	123.47 Hz
4	E3	164.81 Hz
3	G#3	207.65 Hz
2	B3	246.94 Hz
1	E4	329.63 Hz

Open C

String	Note	Frequency (A = 440 Hz)
6	C2	65.41 Hz
5	G2	98.00 Hz
4	C3	130.81 Hz
3	G3	196.00 Hz
2	C4	261.63 Hz
1	E4	329.63 Hz

Half step down (E♭)

String	Note	Frequency (A = 440 Hz)
6	D#2	77.78 Hz
5	G#2	103.83 Hz
4	C#3	138.59 Hz
3	F#3	185.00 Hz
2	A#3	233.08 Hz
1	D#4	311.13 Hz

Whole step down (D)

String	Note	Frequency (A = 440 Hz)
6	D2	73.42 Hz
5	G2	98.00 Hz
4	C3	130.81 Hz
3	F3	174.61 Hz
2	A3	220.00 Hz
1	D4	293.66 Hz

Drop C

String	Note	Frequency (A = 440 Hz)
6	C2	65.41 Hz
5	G2	98.00 Hz
4	C3	130.81 Hz
3	F3	174.61 Hz
2	A3	220.00 Hz
1	D4	293.66 Hz

Other guitar tunings

How to tune, step by step

Tap “Turn on microphone” and allow access. On a phone, hold it close to the body or the pickup of the instrument.
Play one open string and let it ring. The tuner recognises the nearest string of the selected tuning and highlights it.
If the note is flat, tighten the peg. If it is sharp, loosen below the note and come back up: finishing on a tightening turn keeps the string from slipping flat on the first strum.
When it turns green the string is within ±5 cents. Move to the next one, and when you finish go round once more: tightening some strings shifts the others slightly.

Sound Tools, the app

The same tuner on iPhone, Apple Watch and Android, offline, with an instrument catalogue and every string turning green within ±5 cents. Plus a metronome, a spectrum analyzer and a chord and key detector. Free, no account.

Get it on Google Play Download on the App Store

Frequently asked questions

What is the standard tuning for guitar?

Standard (EADGBE): E2 A2 D3 G3 B3 E4, from string 6 to string 1, with the reference A at 440 Hz.

Does it work with my phone’s microphone?

Yes. It works in any current browser — Chrome, Safari, Firefox or Edge — on Android, iPhone or desktop. It only needs permission to use the microphone.

Is my audio recorded or sent anywhere?

No. The analysis runs in your browser and the sound never leaves your device.

Can I tune to 442 or 432 Hz?

Yes: change the “A =” field and every string is recalculated. Anything from 400 to 480 Hz works.

Is there an app to tune offline?

Yes: Sound Tools for iPhone, Apple Watch and Android, free and without an account. It has these same tunings plus a metronome and a chord detector.

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