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Free online guitar tuner

Tune your guitar in the browser: play a string and the needle shows how many cents you are sharp or flat, or play a reference tone and tune by ear. Presets cover standard tuning, Drop D, DADGAD, Open G, 4-string bass and ukulele. The microphone sound is analysed on your device and never sent anywhere.

Two ways to tune

With the microphone. Allow microphone access, play one string and let it ring. The tuner detects the note, and the needle shows the distance in cents: 100 cents make one semitone, so a reading of +20 means you are a fifth of a semitone sharp. Aim for the centre, within about 5 cents. The audio is analysed in your browser and never leaves your device.

By ear with reference tones. Click a string to hear its target note, then match it. This is the method to use in a noisy room, and it trains your ear at the same time. Listen for the slow wobble (called beating) when your string is close to the reference: the slower the wobble, the closer you are. When it disappears, you are in tune.

Standard tuning: notes and frequencies

Standard tuning is E A D G B E, from the thickest string to the thinnest. The numbers after each note give the octave in scientific pitch notation (A4 = 440 Hz).

A handy memory phrase: Eddie Ate Dynamite, Good Bye Eddie. Guitar music is written an octave higher than it sounds, which is why the low E looks like E3 on a score.

Alternate tunings and other instruments

The presets set the target notes for you, from low to high:

In Drop D only the 6th string moves, down a whole step to D: one finger across the three lowest strings now plays a power chord. DADGAD lowers three strings and gives a ringing Dsus4 when strummed open. Open G is an open tuning: the open strings form a G major chord, a favourite for slide and Keith Richards style riffs. The ukulele is re-entrant: its G string is higher than the C next to it (see ukulele tuning).

Want to know which chord shapes and scales work in these tunings? The free GuitarHarmony workshop (free account) has an alternate tunings tool that redraws chords and scales for Drop D, Open G, DADGAD and more.

Tuning tips from the teaching room

• Tune up to the note. If a string is sharp, go below the target and come back up. The string settles better and stays in tune longer.
• Pick the string softly, then wait a second. A hard attack pushes the pitch sharp for a moment; read the needle once the note has settled.
• Check with a chord. Once all six strings read in tune, strum an E minor chord or a G major. If something still sounds sour, recheck the G and B strings first, they are the most sensitive.
• New strings stretch. Expect to retune several times in the first hour.
• Tune again after a capo or a big temperature change. Both shift the pitch slightly.

Tuning by ear without a reference

If you only have one string in tune, the classic 5th-fret method gets you the rest:

1. Fret the low E string at the 5th fret: that is A, match the open 5th string to it.
2. 5th fret of the A string gives D for the open 4th string.
3. 5th fret of the D string gives G for the open 3rd string.
4. 4th fret of the G string gives B for the open 2nd string (the one exception, because G to B is a major third, not a fourth).
5. 5th fret of the B string gives E for the open 1st string.

Every step compares two notes a perfect fourth apart from the open strings. Use the tuner afterwards to see how close your ear got.

How to use it

1. Choose a preset. Guitar standard is selected by default. Switch to Drop D, DADGAD, Open G, 4-string bass or ukulele if you need to.
2. Allow the microphone. Your browser asks for permission once. The sound is analysed locally and never sent anywhere. Prefer to tune by ear? Skip this and use the reference tones.
3. Play one string at a time. Let the string ring and watch the needle. Left of centre means flat (tighten), right of centre means sharp (loosen, then come back up).
4. Check the whole guitar. Go through all the strings twice: adjusting one string slightly changes the tension on the neck and can pull the others out.

What you can do with it

Your first guitar

Beginners often play out of tune without noticing, and every chord sounds wrong. Tune with the needle before each session, then strum a G chord: you will start to recognise what in tune sounds like.

Switching to Drop D for a song

Select the Drop D preset, lower only the 6th string until the needle centres on D, and check it against the open 4th string an octave higher. Back to standard after the song in ten seconds.

Tuning a bass or ukulele in the same lesson

Teachers with a mixed group switch presets instead of carrying three tuners. The reference tones also let students tune by ear while the teacher checks the needle.

More free tools

• Free music tools
• Online metronome
• Online piano
• Online drum machine
• Blank sheet music paper
• Guitar chord charts
• Piano chord charts
• Scales dictionary

Ready to go further than the chart?

The free GuitarHarmony workshop shows every scale on the whole neck, names any chord you play and builds progressions with you. Free account, no card.

Try it free