Online guitar tuner
Tune a guitar, bass or ukulele with your phone or computer microphone. Play one string; the needle shows whether it is flat or sharp.
Press Start and allow the microphone. Then play one string at a time.
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Reference tones (tap to hear the target pitch):
Sound is analysed only in this tab. Nothing is recorded or uploaded.
How to tune a guitar with this tuner
- Press Start tuner and allow the microphone. On a phone, hold it close to the sound hole or the amp speaker.
- Pick one string and let it ring. The big letter shows the nearest note; the needle and the cents number show how far off it is.
- If the needle is left of centre (negative cents) the string is flat: tighten it. Right of centre (positive cents) is sharp: loosen it.
- Within about ±5 cents the note turns green. That is closer than most ears can hear.
- Standard tuning from the thickest string is E2 A2 D3 G3 B3 E4. The string buttons light up for the string you are closest to.
- Tune slightly below the note and come up to it. Strings settle better when tightened into pitch than when loosened.
Tips for an accurate reading
- Quiet the room. Fans, voices and other strings ringing confuse any microphone tuner. Mute the strings you are not tuning.
- Pluck firmly, then read the needle after the first second; the attack of a note is always a little sharp.
- Low strings need a moment: the bass E (41 Hz) has a slow cycle, so give it a full second to settle.
- Electric guitars: unplugged strings are quiet, so put the phone right on the body near the pickups, or tune through the amp.
- If your band or a recording sits slightly off concert pitch, change Reference A4 (for example 432 or 442 Hz) and every target follows.
Alternate tunings
Drop D lowers only the thickest string to D for heavier riffs. Half step down (E flat) lowers every string by one semitone, as many rock players use. Open G and Open D make a chord when you strum all open strings, which suits slide guitar. DADGAD is popular in folk and Celtic music. Pick the tuning in the list and the targets and reference tones change with it.
Questions
Is this online guitar tuner accurate?
It measures pitch from the microphone signal and shows it to about one cent. Accuracy depends mostly on a clean, single note and a quiet room; a phone microphone is fine for tuning.
Can I tune a bass or ukulele here?
Yes. Choose Bass (E A D G) or Ukulele (G C E A) in the Tuning list. The tuner itself is chromatic, so it reads any note.
Why does the note jump around?
Other sounds or ringing strings are being picked up, or the note has faded. Mute the other strings, pluck again and hold the phone closer.
Does the tuner work on iPhone?
Yes, in Safari or Chrome. Allow the microphone when asked. For tuning on stage or without signal, the app works offline.
Is my audio recorded?
No. The sound is analysed in this browser tab only and nothing is stored or sent anywhere.
From the same developer
- Guitar Tuner: Chromatic: the iPhone tuner with auto string detection.
- Online metronome: practise in time after you tune.