Guitar tuner

Standard guitar tuning is E A D G B E (E2, A2, D3, G3, B3, E4), thickest string to thinnest. Tap Use microphone and play one string: the needle shows if it is flat (tighten) or sharp (loosen). No mic? Tap a string button to hear its note and match it by ear.

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Tap the microphone button, then play one string.

Microphone off. Your audio is analyzed in this browser tab and never uploaded.

Reference tones: tap a string to hear its target note.

How to use the tuner

Tap Use microphone and allow microphone access when the browser asks.
Pluck one open string and let it ring. Keep the others quiet.
The big letter shows the nearest string note. The needle and the cents readout show how far off you are: a negative number means flat (turn the peg to tighten), a positive number means sharp (loosen).
When the reading stays within 5 cents, the note changes color and the readout says "in tune". Move to the next string.
Go through all six strings, then check them once more. Tuning one string changes the neck tension a little, so a second pass tightens everything up.

Privacy: the microphone audio is processed right here in your browser to measure its pitch. It is never recorded, stored or uploaded.

Standard tuning explained

Guitarists number strings from the thinnest (1st, high E) to the thickest (6th, low E). Both E strings are the same letter, two octaves apart.

String	Note	Reference
1st string	E4
2nd string	B3
3rd string	G3
4th string	D3
5th string	A2
6th string	E2

A common way to remember E A D G B E is "Eddie Ate Dynamite, Good Bye Eddie". Most chord shapes and every chart on the guitar chord pages assume this tuning.

How to tune by ear: the 5th-fret method

If you have one string in tune (from the reference tone, a piano, or another instrument), you can tune the rest to it. Neighboring strings are tuned so that a fretted note on one matches the next string open.

Tune the low E string (6th) to the reference tone.
Press the 6th string at the 5th fret. It should sound the same as the open 5th string (A). Turn the 5th string's peg until the two match.
Press the 5th string at the 5th fret. It should sound the same as the open 4th string (D). Turn the 4th string's peg until the two match.
Press the 4th string at the 5th fret. It should sound the same as the open 3rd string (G). Turn the 3rd string's peg until the two match.
Press the 3rd string at the 4th fret. It should sound the same as the open 2nd string (B). Turn the 2nd string's peg until the two match.
Press the 2nd string at the 5th fret. It should sound the same as the open 1st string (E). Turn the 1st string's peg until the two match.

Notice the one exception: the G string uses the 4th fret, not the 5th, to match the B string. When two notes are close but not quite matched you'll hear a slow "wobble" (called beating). Turn slowly until the wobble disappears. More about why this works is on guitar fretboard notes.

Alternate tunings

Changing the open strings changes which chords are easy and how the guitar rings. These are the most common. Tune to them by ear from standard: the changed strings are in bold.

Tuning	Strings, 6th to 1st	Used for
Drop D	D A D G B E	Heavy riffs and power chords played with one finger across the three low strings.
DADGAD	D A D G A D	Celtic and folk fingerpicking; open strings ring against fretted notes.
Open G	D G D G B D	Slide guitar and blues; strumming the open strings gives a G major chord.
Open D	D A D F♯ A D	Slide and fingerstyle; the open strings make a D major chord.
Half step down	D♯ G♯ C♯ F♯ A♯ D♯	Every string one half step lower; common in rock for a heavier sound and easier bends.

In Drop D, lower only the 6th string until its open note matches the D string (4th) an octave below; the 7th fret of the lowered string will then match the open A string. Chord diagrams on this site use standard tuning, so tune back before using them.

Troubleshooting

"The browser did not allow the microphone": check the site permissions (the lock or settings icon in the address bar) and allow the microphone, then reload. On iPhone, also check Settings for your browser's microphone access.
The reading jumps between notes: mute the strings you are not tuning, pluck with medium force, and read in the first second after the pluck.
The tuner shows a note an octave off or a neighbor string: the string is far out of tune. Play its reference tone, get close by ear, then use the mic.
A string won't stay in tune: new strings stretch for a day or two. Tune, gently pull each string away from the fretboard, and tune again.
Everything is in tune but chords sound off higher up the neck: that's intonation, a setup issue a guitar shop can adjust.

Other tuners and tools

Tuning a different instrument? Use the ukulele tuner or the bass tuner. Once you're in tune, try the first guitar chords and keep time with the metronome. All free tools are on the tools page.

Guitar tuner questions

What are the standard guitar tuning notes?

From the thickest (6th) string to the thinnest (1st): E2, A2, D3, G3, B3, E4. Written as letters: E A D G B E.

Does this guitar tuner record or upload my audio?

No. The microphone signal is analyzed by JavaScript inside your browser tab to find the pitch, and nothing is recorded, stored or sent to a server. Press the microphone button again, or close the tab, to turn the microphone off.

Why does the tuner jump around or show the wrong note?

Usually background noise, two strings ringing at once, or the note fading. Mute the other strings, pluck firmly near the middle of the string, and read the tuner in the first second or two after you pluck.

Should I tune up or down to the note?

Tune up to the note. If a string is sharp, loosen it below the target first, then bring it back up. The gear holds its position better that way and the string stays in tune longer.

Can I tune an acoustic and an electric guitar with this?

Yes. For an electric, play it through an amp or hold the phone close to the strings, since an unplugged electric is quiet. Standard tuning is the same on both.

Updated September 2026.