Guitar tunerBeta
Free online guitar tuner
Press start, allow the microphone and play a string. The tuner finds the string and shows how far it is in cents. Guitar, bass, ukulele or chromatic.
- Free
- No sign-up
- Runs in your browser
- Nothing is uploaded
Loading the tool
How it works
- 01
Start the tuner
Press start and allow the microphone. The sound stays on your device; nothing is recorded or uploaded.
- 02
Play one string
Pluck a single open string and let it ring. The tuner picks the nearest string of your tuning and shows the note.
- 03
Follow the needle
Left means flat, so tighten the string; right means sharp, so loosen it. Green means in tune, within three cents.
How to tune a guitar
Standard tuning, from the thickest string to the thinnest, is E2 A2 D3 G3 B3 E4. A common way to remember it: Eddie Ate Dynamite, Good Bye Eddie. Start with the low E and work across.
Pluck one open string at a time, firmly but not hard, and let it ring. The note jumps sharp for a moment on a hard attack, then settles; read the needle once it is steady. If the needle sits left of centre the string is flat, so turn the peg to tighten it. If it sits right the string is sharp, so loosen it.
Always finish by tuning up to the note. If you go past it, drop below and come back up. The string then holds its tension against the gear and stays in tune longer. When all six are green, play a chord and check them once more: tuning one string pulls a little on the neck and changes the others.
Alternate tunings
Drop D lowers only the low E to D (D2 A2 D3 G3 B3 E4). Power chords become one finger, and it is a staple of rock and metal. DADGAD (D2 A2 D3 G3 A3 D4) gives an open, droning sound loved in folk and Celtic music.
Open tunings make a chord with the open strings. Open G (D2 G2 D3 G3 B3 D4) is the tuning of a lot of slide and blues guitar. Open D (D2 A2 D3 F#3 A3 D4) and open E (E2 B2 E3 G#3 B3 E4) do the same in other keys.
Half step down (Eb Ab Db Gb Bb Eb) and full step down (D G C F A D) keep the shapes of standard tuning but sound lower, easier on the voice and on the fingers with heavy strings. Drop C is full step down with the low string dropped one more step.
Pick the tuning in the menu and the tuner listens for those strings. You can switch back to standard at any time.
Bass, ukulele and chromatic mode
A 4 string bass is E1 A1 D2 G2, an octave below the four lowest guitar strings; a 5 string adds a low B0. Low notes are slow to measure, so give a bass string a second to settle before you read the needle. A phone's small microphone hears the low B weakly; plug-in headphones with a mic, or holding the phone close to the speaker of your amp, helps.
A standard ukulele is G4 C4 E4 A4, with the G higher than the C (re-entrant). Low G tuning drops it an octave to G3, and a baritone ukulele is tuned like the top four strings of a guitar, D3 G3 B3 E4.
Chromatic mode shows the nearest note of any sound: a violin, a voice, a horn, a piano that needs a check. It works for any instrument with a clear pitch.
Calibration: A4 = 440 Hz and the others
Most music today is tuned to A4 = 440 Hz. Some orchestras tune a little higher, to 442 or 443 Hz, and some players like 432 Hz. If you are playing along with a record or a piano that is not at 440, set A4 to match it and every string moves with it. The setting goes from 430 to 446 Hz and is remembered on this device.
What you get
- Guitar tunings: standard, drop D, half and full step down, drop C, DADGAD, open G, open D and open E
- Bass: 4 string, 5 string, drop D and half step down
- Ukulele: standard GCEA, low G and baritone
- Chromatic mode for any instrument or voice
- Finds the string by itself, with the note name and octave
- A needle in cents, accurate to a fraction of a cent on a steady tone
- A4 calibration from 430 to 446 Hz
- A reference tone for every string, to tune by ear
- Runs in your browser: nothing recorded, nothing uploaded, no sign-up
Which kind of tuner?
| OBRA online tuner | Clip-on tuner | |
|---|---|---|
| Cost | Free | A small purchase |
| Hears | The microphone, so the room too | The vibration of the headstock |
| Best in | A quiet room | Noisy rooms and on stage |
| Tunings | Guitar, bass, ukulele and chromatic | Usually chromatic |
| Reference tone | Yes, for every string | Rarely |
At home, a microphone tuner is all you need. On a loud stage, a clip-on or pedal tuner that does not hear the room is easier.
Frequently asked questions
How do I tune my guitar with my phone?
Open this page on your phone, press start and allow the microphone. Play one open string, hold the phone near the guitar, and turn the peg until the needle is in the middle and turns green.
Is an online guitar tuner accurate?
Yes, in a quiet room. On a steady tone this tuner is accurate to a fraction of a cent, far finer than the ear can hear. Background noise, other strings ringing and a very hard pluck make any microphone tuner wobble, so pluck one string at a time and let it settle.
Why does the needle jump around?
Usually because other strings are ringing, the room is noisy, or the string was plucked very hard. Mute the other strings with your hand, pluck softly with the thumb near the neck, and read the needle after the first moment.
What is the standard guitar tuning?
From the thickest string to the thinnest: E2 A2 D3 G3 B3 E4. The low E is about 82.4 Hz and the high E about 329.6 Hz at A4 = 440 Hz.
Can I tune a bass or a ukulele?
Yes. Choose bass for 4 or 5 strings, drop D or half step down, or ukulele for standard GCEA, low G or baritone. Chromatic mode covers anything else.
Does the tuner record me?
No. The microphone is read in your browser to measure the pitch. Nothing is recorded, saved or sent anywhere. The microphone stops when you press stop or leave the page.
What does the reference tone do?
Tap a string's note to hear a plucked tone at that pitch, so you can tune by ear. It follows your A4 setting.
The microphone is blocked. What do I do?
Your browser asked for permission and it was refused. Click the lock or the camera icon next to the address, allow the microphone for this site, and press start again. On a phone, check that the browser has microphone access in the system settings.
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Finish the track
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