Your microphone audio is analyzed locally, in your browser. It is neither recorded nor transmitted.
This free online guitar tuner works directly with your computer, phone, or tablet microphone, with nothing to install. Authorize microphone access, play an open string, and the tuner displays the detected note. Just adjust the string until the needle settles in the green zone. It uses standard EADGBE tuning and the A440 reference pitch.
How to tune your guitar online
- Allow microphone access when your browser prompts you.
- Play one open string at a time, close to the microphone.
- Watch the detected note and turn the tuning peg until the indicator stabilizes in the green zone. Repeat for all six strings, from low E to high E.
A tip that makes all the difference: approach the target note by tuning up (if the string is too high, drop below the note then come back up) so the tuning holds better. The complete method, including tuning by ear and harmonics, is in the complete guide to tuning your guitar.
The six string notes and their frequencies
| String | Note | Scientific notation | Frequency | Gauge |
|---|---|---|---|---|
| String 1 | High E | E4 | 330 Hz | thinnest |
| String 2 | B | B3 | 247 Hz | thin |
| String 3 | G | G3 | 196 Hz | medium |
| String 4 | D | D3 | 147 Hz | medium |
| String 5 | A | A2 | 110 Hz | thick |
| String 6 | Low E | E2 | 82 Hz | thickest |
The reference for all tuners is A (A4) at 440 Hz, the standard pitch. And if you wonder why the guitar is tuned to EADGBE, the complete answer is in our fretboard guide.
How a microphone tuner works
The tuner listens to your string’s sound through the microphone and measures its vibration frequency, expressed in Hertz (Hz). Each note has a precise frequency: the A on a tuning fork vibrates at 440 Hz, your low E at about 82 Hz (the frequency of a note in Hertz, if you want to dig deeper). The tuner compares the captured frequency to the string’s target frequency and tells you if it’s too low, too high, or right on, in the green zone. It’s a physical measurement, not an opinion. What some call a “tuner” does nothing more than count vibrations.
Frequently asked questions about the tuner
Is this online guitar tuner reliable?
Yes, an online microphone tuner is reliable as long as it picks up the string’s sound clearly. It measures vibration frequency just like a physical tuner, comparing it to each note’s target frequency. For accurate results, it’s best to play in a quiet environment, one string at a time, and let the note ring out. Background noise or multiple strings played together can interfere with detection.
How do I tune my guitar without a microphone or offline?
If you can’t use a microphone, you can tune your guitar by ear using the 5th fret method, which compares each string to the previous one. You press the 5th fret of a string to match the next open string, with one exception at the 4th fret for tuning the B string. This method requires no equipment. The complete method, including harmonics and tuning entirely by ear, is detailed in our dedicated article on guitar tuning.
What note corresponds to each guitar string?
In standard tuning, the six strings are, from lowest to highest: E, A, D, G, B, and E. Strings 6 and 1 are both E notes, separated by two octaves. Their frequencies range from 82 Hz for low E to 330 Hz for high E, passing through A at 110 Hz. The common reference is A at 440 Hz, which all tuners align to.
Why does my guitar go out of tune so quickly?
Several causes combine: new strings stretching, temperature and humidity variations, poorly wound strings around the tuning pegs, or tuning down to the note rather than up. A guitar that constantly goes out of tune deserves checking these points one by one. We detail the causes and solutions in our article on guitar tuning.
Do I need to install an app to use this tuner?
No, this tuner works directly in your browser, with no installation or account creation required. Simply allow microphone access to start tuning. It works on computers, phones, and tablets, as long as the device has a microphone and a recent browser. It’s a free tool, designed to be used in seconds.
Go further: understand your guitar fretboard
Is your guitar tuned? Now’s the perfect time to understand what you just did. Our series understanding your guitar fretboard explains, with interactive visuals and real sounds: why these six notes, how the fretboard works fret by fret, how to find any note and read any chord. The tuner gets you started. The series makes you independent.