Free online guitar tuner with standard tuning (E-A-D-G-B-E) and Drop D. Real-time pitch, frequency and cents detection from your microphone. Works for acoustic and electric guitar; audio is processed locally in your browser.
How to tune: Guitar
- Pick a tuning above (if unsure, keep the first, standard one).
- Press “Start tuning” and allow the microphone in the browser prompt.
- Play one string at a time close to the mic and wait for a steady reading.
- Needle left (flat): tighten. Needle right (sharp): loosen. The green zone means in tune.
Start from the thickest string and work up: 6th string E2, 5th A2, 4th D3, 3rd G3, 2nd B3, 1st E4. A needle to the left means flat, so tighten the string; to the right means sharp, so loosen it. The central green zone is in tune. On a new set of strings, or an instrument that has not been tuned in a while, do a rough pass first and then fine-tune.
Guitar frequencies (A4 = 440 Hz)
| String | Note | Frequency (Hz) |
|---|---|---|
| String 6 | E2 | 82.41 |
| String 5 | A2 | 110.00 |
| String 4 | D3 | 146.83 |
| String 3 | G3 | 196.00 |
| String 2 | B3 | 246.94 |
| String 1 | E4 | 329.63 |
Guitar tuning tips
Point the soundhole at the microphone on an acoustic; on an electric you can play straight into the pickup — the standard tuning is identical. Wait one or two seconds after the attack before reading, because low strings need a longer sustain. Stretch new strings gently a few times before tuning to cut down on drift. Drop D only lowers the 6th string to D2; the other five stay the same.
Is microphone audio uploaded?
No. Web Audio analyzes sound in real time on your device. This page does not record, upload or store microphone audio.
Frequently asked questions
Can I use the same tuner for acoustic and electric guitar?
Yes. Both use the same standard tuning (E-A-D-G-B-E). On an electric, just play toward the pickup — no amp needed.
How do I tune to Drop D?
Pick Drop D in the tuning preset. Only the 6th string drops from E2 to D2; the other five strings keep their standard pitch.
Why is the reading so slow on the low strings?
Low strings have a long vibration period, so the detector needs more samples. Hold the note for two to three seconds, or play again closer to the microphone.
My new strings keep going out of tune. What helps?
New strings stretch. Pull them gently a few times after fitting, tune, play for a bit, then tune again — two or three rounds usually settles them.
