Free online guitar tuner
Tune your acoustic, classical or electric guitar right here in your browser. Allow the microphone, pluck a string – Exact Tune recognises which string you play and shows how many cents you are off.
The needle moves smoothly instead of jumping, and the note turns green when the string is in tune. No ads, no account, nothing to install.
- Standard tuning E A D G B E
- Automatic string detection
- Accurate to about 1 cent
- Reference tone for every string
Standard guitar tuning – string frequencies
| String | Note | Frequency |
|---|---|---|
| 6 (thickest) | E2 | 82.41 Hz |
| 5 | A2 | 110.00 Hz |
| 4 | D3 | 146.83 Hz |
| 3 | G3 | 196.00 Hz |
| 2 | B3 | 246.94 Hz |
| 1 (thinnest) | E4 | 329.63 Hz |
A4 = 440 Hz
Guitar tuner questions
How do I tune my guitar online?
Open the tuner on this page, allow microphone access and pluck one string at a time. Turn the tuning peg until the needle is in the middle and the note turns green.
What is standard guitar tuning?
From the thickest to the thinnest string: E2 (82.41 Hz), A2 (110 Hz), D3 (146.83 Hz), G3 (196 Hz), B3 (246.94 Hz) and E4 (329.63 Hz), with A4 = 440 Hz.
Does it work for classical and electric guitars?
Yes. Acoustic, classical and electric guitars all use the same standard tuning. For an electric guitar, hold the phone close to the amplifier or the strings.
Is the online guitar tuner free?
Yes, completely free, without ads or sign-up. There is also a free Android app that works offline.