Guitar Tuner: Tune Your Guitar Online

How to tune your guitar with this online tuner

1. Press Start tuner and allow microphone access when the browser asks. On a laptop or phone the built-in microphone works well; hold the guitar's sound hole or the phone within about 30 cm of each other.
2. Choose your Instrument (Guitar, Bass, Ukulele, Violin or Chromatic) and, for a guitar, the Tuning: Standard, Drop D, Half step down, DADGAD, an open tuning and so on.
3. Pluck one open string and let it ring. In Auto mode the tuner picks the nearest string of the tuning and shows its note, the frequency it hears and how many cents it is off.
4. Follow the needle and the hint: Too low: tune up means tighten the string, Too high: tune down means loosen it. When the needle sits in the green zone (within 5 cents) the display turns green and says In tune, and the string gets a tick.
5. Repeat for every string. If the tuner keeps choosing the wrong string (a very slack string can be closer to its neighbour), tap the string you are tuning to lock the tuner onto it. Tapping a string also plays its note, so you can tune by ear; turn this off with Play the note when I tap a string.

Press Stop when you are done. If your band or a recording uses a different concert pitch, set Reference pitch A4 between 430 and 450 Hz (440 Hz is the usual standard; some orchestras tune to 442 Hz).

Standard guitar tuning: notes and frequencies

From the thickest string (6th) to the thinnest (1st), standard tuning is E A D G B E. With A4 at 440 Hz the target frequencies are:

The other presets are Drop D (D A D G B E), Half step down (E♭ A♭ D♭ G♭ B♭ E♭), Full step down or D standard (D G C F A D), Drop C (C G C F A D), Drop B (B F♯ B E G♯ C♯), DADGAD, Open G (D G D G B D), Open D (D A D F♯ A D) and Open E (E B E G♯ B E). Bass uses E A D G an octave below the guitar's four lowest strings (or D A D G in drop D), a ukulele G C E A with a high or low G, a baritone ukulele D G B E, and a violin G D A E. For any other instrument or tuning, the Chromatic mode shows the nearest of all twelve notes.

How the tuner works, and how accurate it is

About 25 times a second the tuner takes the last tenth of a second of sound from the microphone and looks for the time after which the waveform repeats itself (its period), using the YIN method from speech and music research. The frequency is the inverse of that period; interpolation between samples gives a resolution far below one cent. A plucked guitar string is rich in overtones, and its second harmonic is often louder than the fundamental, which is why simple tuners jump an octave up. This tuner looks for the longest clear period first, keeps a median of the last few readings and ignores one-off octave jumps, so the low E reads as E2 and not E3. On clean synthetic test tones it is accurate to well within one cent, including the bass's low E1 (41.2 Hz).

In real use, accuracy depends on the sound reaching the microphone. A quiet room and a single ringing string give a steady reading; background music, other strings ringing or a phone's noise filter can make the needle wander. Read the needle a second or so after the pluck, once the initial attack has settled, and tune up to the note (see the FAQ). Bluetooth headsets often switch to a low-quality microphone mode, so the device's own microphone is usually better. If nothing happens, check your input with the mic test or follow the guide microphone not working.

For more detail on tuning methods, including the 5th-fret method and harmonics, read how to tune a guitar by ear and with a tuner. Once you are in tune, practise in time with the online metronome, or find chords and melodies on the online piano.

Privacy

The microphone only switches on after you press Start tuner and allow access. The sound is analysed in your browser, a few times per second, and is never recorded, stored or uploaded; there is no server involved. Press Stop, switch to another tab or close the page and the microphone is released. Your choices (instrument, tuning, reference pitch and the tap sound switch) are kept in this browser's local storage so the tuner opens the way you left it.

Frequently asked questions

How do I tune a guitar with this online tuner?

Press Start tuner, allow the microphone, choose Guitar and your tuning, then pluck one open string at a time. Turn the tuning peg until the needle is in the green zone and the tuner says In tune. Tighten the string when it says tune up and loosen it when it says tune down.

What are the notes of the guitar strings?

In standard tuning, from the thickest to the thinnest string: E, A, D, G, B, E (E2, A2, D3, G3, B3 and E4). A common way to remember them is "Eddie Ate Dynamite, Good Bye Eddie".

Why does the tuner jump between notes?

Usually because more than one sound reaches the microphone: other strings ringing, background noise, or the sharp attack right after the pluck. Mute the strings you are not tuning, pluck firmly but not hard, and watch the reading after the first moment. If it still picks the wrong string, tap that string in the tuner to lock onto it.

Can I tune a ukulele or bass?

Yes. Choose Ukulele for G C E A (high or low G) or baritone D G B E, or Bass for E A D G and drop D A D G. The low E of a bass, at about 41 Hz, is found from the repeating pattern of the whole sound, so it can still be detected when a small microphone barely picks up the fundamental itself. Chromatic mode covers any other instrument.

Does the tuner record my audio?

No. The sound is analysed on your device a few times per second and immediately discarded; nothing is recorded, saved or sent anywhere. The microphone only switches on after you press Start tuner, and Stop releases it.

What is Drop D tuning?

Drop D lowers the 6th string by a whole step, from E to D, so the strings read D A D G B E. It gives a deeper bass note and lets you play power chords on the three lowest strings with one finger. Choose Drop D in the Tuning list and tune the low string down until the tuner shows D2 in tune.

Updated 2026-10-16