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Guitar tuner
Tune your acoustic, classical or electric guitar with your microphone: play a string, the tuner finds the nearest string of standard tuning (E A D G B E) and the needle shows whether to tighten or loosen it.
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How it works
Allow the microphonePress Start tuner and allow microphone access in your browser.
Pick your instrumentChoose a preset, or keep Chromatic to see the nearest note.
Tune until it turns greenPlay one string at a time and turn the peg until the needle sits in the middle.
Standard tuning, string by string
Standard guitar tuning from the thickest to the thinnest string is E2, A2, D3, G3, B3 and E4, which is 82.4, 110, 146.8, 196, 246.9 and 329.6 Hz with A4 at 440 Hz. Start with the low E string and work your way up: tightening one string slightly changes the tension on the neck, so a second pass is often worth it, especially with new strings.
If a string is far off, the tuner may think you are playing a neighbouring string. Press the string button to lock it, tune until the needle is green, then press Auto again. Play reference plays the note of that string if you prefer to tune by ear.
Alternate tunings
The instrument list also has drop D (D A D G B E), half step down (all strings a semitone lower, common in rock and blues), open G (D G D G B D, for slide and Keith Richards style riffs) and DADGAD (popular in folk and fingerstyle). For other tunings, switch to Chromatic and tune each string to the note you need.
Electric guitars tune most reliably from the neck pickup with the tone control open. On an acoustic guitar, point the sound hole towards the microphone.
Frequently asked questions
In what order should I tune the strings?
From low E to high E, then check all strings once more. Changing the tension of one string pulls the neck a little, so the others may shift slightly.
My string keeps going out of tune. Why?
New strings stretch for the first days and drop in pitch. Gently pull each string away from the fretboard along its length, retune and repeat a few times. Temperature changes also affect tuning.
Can I tune a 12 string or 7 string guitar?
Use Chromatic mode and tune each string to its note. The octave strings of a 12 string guitar are tuned an octave above their partners, except the B and high E pairs, which are tuned in unison.
Is my microphone recorded?
No. The sound is analysed in your browser a few dozen times per second and then discarded. Nothing is saved or sent anywhere, and the microphone turns off when you press Stop, leave the page or switch to another tab.
How accurate is the tuner?
With a clean tone it reads within a fraction of a cent. Real strings contain overtones that are slightly sharp, so readings can move by a few cents while a note rings; aim for the needle to settle in the green zone and you are well tuned.
Why does the tuner show the wrong octave or note?
Loud overtones or background noise can confuse any tuner for a moment. Play a single string, mute the others and move closer to the microphone. With an instrument preset you can also lock the tuner to one string.
What does drop D mean?
In drop D the lowest guitar string is tuned a whole tone down from E to D, the other strings stay as in standard tuning. It gives a deeper sound and power chords with one finger. Choose Guitar, drop D in the instrument list.
Does it work on a phone?
Yes, in current browsers on Android and iPhone. Allow the microphone when asked; on iPhone, tuning works best with the phone close to the instrument.
Is the tuner free?
Yes, free without sign-up or ads inside the tool. It also works without an internet connection once the page has loaded.