Online Guitar Tuner
Tune your guitar online with your microphone. Press Start tuner, allow the microphone and play one string: the tuner names the string and shows in cents whether it is too low or too high. Standard tuning is E A D G B E. Nothing is recorded or uploaded.
Guitar tuner
The tuner needs JavaScript and a microphone. The note table and reference frequencies below work without it.
To hear the string you play and measure its pitch. When you press Start, your browser asks for permission. The sound is analysed on this device only: nothing is recorded, saved or uploaded, and the microphone switches off when you press Stop or leave the page.
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Press Start tuner, then play one string
String (Auto finds it for you)
Reference pitch: A4 = 440 Hz
The microphone is blocked for this site. The tuner cannot hear your guitar until you allow it. Nothing else on the page needs it, and you can still use the reference tones below to tune by ear. To allow the microphone:
No microphone was found. Plug in or switch on a microphone (or use a phone or laptop with a built-in one), then press Start again.
The microphone is busy. Close other apps or tabs that use it, such as video calls or recorders, then press Start again.
This browser cannot give the page microphone access. Use a current version of Chrome, Edge, Firefox or Safari, and check that the address starts with https://.
The microphone could not start. Reload the page and try again.
Chrome on a computer
Click the icon to the left of the web address, set Microphone to Allow, then reload the page.
Microsoft Edge
Click the lock icon to the left of the web address, open Permissions for this site, set Microphone to Allow and reload.
Firefox
Click the crossed-out microphone icon in the address bar, clear the blocked permission, reload the page and choose Allow when asked.
Safari on a Mac
Open Safari, Settings, Websites, Microphone, and set onlineguitartuner.app to Allow or Ask. Then reload the page.
iPhone or iPad
Tap the page menu (aA or the settings icon) in the address bar, open Website Settings and set Microphone to Allow or Ask. Then reload the page.
Chrome on Android
Tap the icon to the left of the web address, open Permissions and turn on Microphone. Then reload the page.
Reference tones (tune by ear)
Reference tones need JavaScript.
Press a string to hear its note. Press it again to stop. No microphone needed.
How to tune your guitar with this tuner
- Pick your tuning. Standard (E A D G B E) is selected from the start.
- Press Start tuner and allow the microphone when your browser asks.
- Play one open string and let it ring. Auto mode finds the nearest string.
- If the display says Too low, tighten the string. If it says Too high, loosen it.
- Stop when the needle is in the green zone and the display says In tune. Repeat for every string, then check them all once more, because the neck settles as the tension changes.
Tip: tune up to the note. If a string is sharp, loosen it below the note and then tighten it back up, so the string holds its pitch better.
Standard guitar tuning: notes and frequencies
| String | Note | Frequency | |
|---|---|---|---|
| 6 | E2 | 82.41 Hz | Thickest string |
| 5 | A2 | 110.00 Hz | |
| 4 | D3 | 146.83 Hz | |
| 3 | G3 | 196.00 Hz | |
| 2 | B3 | 246.94 Hz | |
| 1 | E4 | 329.63 Hz | Thinnest string |
String 6 is the thickest string, nearest your face when you hold the guitar. String 1 is the thinnest. The same notes are used on acoustic, electric and classical guitars.
Other tunings
The tuner also covers Drop D, half step down, DADGAD, Open G and Open D. Read what they are used for on alternate tunings. For bass, use the bass tuner. To hear notes and chords, try the virtual guitar.
Questions and answers
How do I tune my guitar online?
Press Start tuner and allow the microphone. Play one open string and let it ring. The tuner shows the nearest string and how many cents you are off. Turn the tuning peg until the needle sits in the green zone and the display says In tune, then move on to the next string.
Is the microphone safe and private?
Yes. The browser only gives the page microphone access after you allow it. The sound is analysed on your own device by JavaScript, nothing is recorded, saved or uploaded, and the microphone turns off when you press Stop or leave the page. The site has no ads, analytics or tracking.
What is standard tuning?
Standard guitar tuning is E A D G B E from the thickest string to the thinnest: E2 (82.41 Hz), A2 (110.00 Hz), D3 (146.83 Hz), G3 (196.00 Hz), B3 (246.94 Hz), E4 (329.63 Hz). These frequencies assume the usual reference pitch A4 = 440 Hz.
Why won't my tuner pick up the note?
Check that the browser has microphone access and that no other app is using the microphone. Play one string at a time, close to the phone or laptop, and let it ring. Mute the other strings, keep background noise down, and try again if the string has been retuned far from its note.
How accurate is this tuner?
Pitch is measured with the YIN method and shown in cents (1/100 of a semitone). In our tests with recorded test tones the reading was within 2 cents. A string counts as in tune within 5 cents, which most listeners cannot hear as out of tune.
Last updated October 20, 2026.