Guitar Tuner
Tune your guitar by microphone or by ear with reference tones, in standard, drop D and open tunings.
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Heard — · target —
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Play one open string at a time and let it ring.
This browser can’t listen to your microphone — it has no getUserMedia or Web Audio support. You can still use the reference tones and the frequency chart below to tune by ear. For microphone tuning, try the latest Chrome, Edge, Firefox or Safari over HTTPS.
Standard (E A D G B E)
How it works
Press Start microphone tuner, allow microphone access, and pluck one open string. The page reads the raw waveform from your mic with the Web Audio API and runs an autocorrelation pitch detector on it, which finds the repeating period of the string and turns it into a frequency. That frequency is compared with the nearest note on the equal-tempered scale, and the needle shows how far off you are in cents — a hundredth of a semitone. Anything within ±5 cents counts as in tune; below that, tune up (flat) or down (sharp).
Pick a tuning from the list — standard, drop D, half or full step down, open G, open D, open E or DADGAD — and the chart shows the exact target frequency for each string. Every row has a reference tone you can play if you prefer tuning by ear or your microphone is unavailable. If you play with an ensemble at a different concert pitch, change the A4 reference from 440 Hz (432 Hz and 415 Hz baroque pitch are common) and every frequency recalculates instantly. No audio leaves your device: there is no upload, no recording and no account — the microphone stream is analysed in this tab and thrown away.
Frequently asked questions
How does the microphone guitar tuner work?
Press Start microphone tuner and allow microphone access, then pluck one open string and let it ring. The page reads the raw waveform with the Web Audio API and runs an autocorrelation pitch detector to find the repeating period of the string, which gives its frequency. That frequency is compared with the nearest note and the needle shows how far off you are in cents. Within ±5 cents the tuner says In tune; otherwise it tells you to tune up (flat) or down (sharp). The audio is analysed in this tab and never recorded or uploaded.
What frequency is each guitar string in standard tuning?
With A4 at 440 Hz, standard EADGBE tuning is: string 6 (low E) E2 = 82.41 Hz, string 5 A2 = 110.00 Hz, string 4 D3 = 146.83 Hz, string 3 G3 = 196.00 Hz, string 2 B3 = 246.94 Hz and string 1 (high E) E4 = 329.63 Hz. Pick a different tuning — drop D, half or full step down, open G, open D, open E or DADGAD — and the chart recalculates, and you can copy or download it as a text file.
Can I tune a guitar without a microphone, and can I change the A4 reference pitch?
Yes. Every string in the chart has a Play button that sounds a reference tone at the exact target frequency, so you can tune by ear if your microphone is blocked, missing or too noisy — the tool says so on screen and stays usable. You can also set the A4 reference anywhere from 415 to 466 Hz for 432 Hz tuning, baroque pitch or an ensemble that tunes sharp, and every string frequency updates instantly.