Guitar tuner online

An online tuner that listens to your instrument

This guitar tuner listens through your computer or phone microphone and shows the note, its frequency and the offset in cents, live. The needle leans left when a string is flat and right when it is sharp, and the text reads “Too low”, “In tune” (within 5 cents) or “Too high”.

It also works as a chromatic tuner and as a ukulele tuner, bass tuner or violin tuner. The sound is analyzed in your browser: nothing is sent or recorded.

How to tune your guitar

1. Find a quiet room and keep the microphone 12 to 20 inches from the guitar.
2. Under “Instrument and tuning”, pick “Guitar standard (E A D G B E)”.
3. Click “Start tuner” (or press the space bar) and allow the microphone.
4. Pluck one open string at a time. The nearest string lights up under “Reference notes”.
5. Turn the peg until you read “In tune”. If the string is sharp, go below the note and come back up: tuning up to pitch keeps it from slipping later.

Click a string under “Reference notes” to hear the target pitch for about 2 seconds.

Standard tuning: exact frequencies

With A at 440 Hz, the six strings, from lowest to highest, should read:

A ukulele is tuned G4 (392 Hz), C4 (261.63 Hz), E4 (329.63 Hz) and A4 (440 Hz); the G sits above the C, which is called reentrant tuning. A 4-string bass gives E1 (41.20 Hz), A1, D2, G2; a violin G3, D4, A4, E5.

Alternate tunings included

• Drop D: the low string goes down to D2 (73.42 Hz), a staple of rock riffs.
• Open G (D G D G B D): a G major chord on the open strings, for blues and slide.
• DADGAD: the open tuning of Celtic and folk players.
• Half step down (E♭ A♭ D♭ G♭ B♭ E♭): the low string reads 77.78 Hz.

A440 and other reference pitches

A at 440 Hz is the usual standard; some orchestras tune to 442 or 443 Hz, baroque groups to 415 Hz, and some players prefer 432 Hz. Set “Reference A (Hz)” from 415 to 466 Hz or use “Common references”: every target note is recalculated. At 432 Hz, the low E string should read 80.91 Hz instead of 82.41 Hz.

Cents made simple

A semitone, the distance between two frets, equals 100 cents. The offset is 1,200 × log2(played frequency ÷ target frequency). An A string at 108 Hz instead of 110 Hz is at −32 cents: tighten it. A note at 446 Hz with A at 440 Hz is at +23 cents. Below 5 cents, most ears hear no difference.

Tips for a tuning that holds

• New strings keep stretching for a few days: retune often.
• Check twice: go around all strings again, since each adjustment slightly changes the tension on the others.
• Pluck firmly and let the string ring: the needle settles in about half a second.

Frequently asked questions

Is my audio stored anywhere?

No. The sound is analyzed in the page and discarded. Only your instrument and reference A stay on your device. “Stop” or switching tabs turns the microphone off.

Why does it show a different string from the one I am playing?

The tool picks the string closest to the sound. A string more than a semitone off can be matched to its neighbor: switch to “Chromatic (all notes)” to read the exact note.

Can I tune a ukulele or a bass?

Yes: choose “Ukulele (G C E A)” or “4-string bass (E A D G)”. The tool detects notes from about 40 to 1,500 Hz.

Nothing shows up. What should I check?

Check the microphone permission in your browser and the selected microphone in your system settings. A message explains the cause when access is denied.