Violin tuner: do I tighten or loosen it?
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Play any string
A string tightened well past its note can snap. If the needle doesn't move as you turn, stop: you may be turning another string's peg.
Start the tuner first, then play your A.
How the violin tuner works
Press Start and the tuner asks your browser for the microphone. Nothing listens before that, on any visit, even if you said yes last week.
Then it does one job, about twenty times a second. It takes the last split second of sound and looks for the pattern that repeats in it. The length of that pattern is the pitch. The method comes from Philip McLeod and Geoff Wyvill at the University of Otago, who built it to cope with bright sounds full of overtones, and named the violin as their example. The same step says how clear the pattern is, and that clarity drives the line beside the reading.
That line is the part we care about most. It says one of four things. Too quiet. Not one clear note, which is what a TV, a voice or two strings ringing together usually get. Settling, while the note still wobbles from the pluck or your hand is on the peg. Or steady, once the pitch has held within 8 cents for 0.4 seconds. Only a steady reading gets a number, a cents figure and a turning hint. The needle moves before that, though, so you can watch it while you turn.
The hint has limits on purpose. It shows up only when the note is within 80 cents of a string, a little under a semitone. Farther out, the tuner names the note it heard and how far away it is, and stops there. A string that far off might be the wrong string, a slipped peg or an overtone, and telling a beginner to keep tightening is how E strings snap. Lock a string by tapping it, and if the tuner hears it an octave up, or an octave and a fifth up, it calls that an overtone instead of telling you you're 1,200 cents sharp.
Each target comes from your reference A. At 440 Hz the violin's G, D, A and E sit at 196.00, 293.66, 440.00 and 659.26 Hz, the equal-tempered notes. A teacher who tunes pure fifths down from the A lands the G about 4 cents lower, which still reads as in tune here, because in tune means within 5 cents.
It can't hear chords. Two strings a fifth apart can pass for one lower note, so play one string at a time and let it ring.
Who this is for
You might be a parent with a rented violin and a lesson in ten minutes, and you can't tell by ear whether the A is flat. Or a student tuning before practice, or before an online lesson where the teacher can't reach the pegs. Or an adult a few weeks into guitar or ukulele, with nobody in the room to check.
And if you're the teacher, Copy readings hands you one line to paste into lesson notes.
Beginner questions about tuning a violin, guitar or ukulele
What notes are violin strings tuned to?
G, D, A and E, from the thickest string. In full that's G3, D4, A4 and E5, each a fifth above the last. With the usual A of 440 Hz, they sit at 196.00, 293.66, 440.00 and 659.26 Hz. If your teacher tunes the A higher, every string moves up with it, and the tuner follows as soon as you change the reference.
Which way do I turn a violin peg or fine tuner?
Tighten to raise the note, loosen to lower it. Which direction that is depends on where the peg sits on the scroll, so make a small turn and watch the needle. If it heads the wrong way, turn back. Fine tuners move the note a little at a time, which makes them the safer place to start. Pegs move it a lot. Turn them in small steps, and push gently into the scroll as you go so they hold.
Why does the tuner say my string is an octave off?
Usually it heard an overtone, an octave above the string you picked. A string also rings at two and three times its own pitch, and through a phone's small microphone those overtones can come through louder than the note itself. Lock the string by tapping it, and the tuner names an overtone as an overtone instead of calling you 1,200 cents sharp. Play the string again and let it ring.
Can I tune a violin with a guitar tuner?
Only in chromatic mode. A tuner set to guitar compares every note with the six guitar strings, so your violin's A and E get measured against the wrong targets. Here, pick Violin and the four violin strings are the targets. For anything else (a viola, a cello, a mandolin or a guitar in drop D), pick Chromatic: it names the nearest of all 12 notes.
Should a violin be tuned to 440 or 442?
440, unless your teacher or orchestra says otherwise. A4 = 440 Hz is the international standard tuning frequency, written into ISO 16. Some orchestras tune a little higher, often 442. If you play in one, match it. Open the reference pitch under the strings, set it, and every target moves with it. The reference stays printed beside the reading, so you always know which one you tuned to.
Why does my violin keep going out of tune?
Mostly three things. New strings keep stretching for a while. Wooden pegs slip. And changes in heat and humidity move both the strings and the wood. None of that means the violin is broken. It's the reason teachers ask you to tune at the start of every practice. If a peg won't hold at all, that's a job for your teacher or a violin shop.
How do I tune an electric guitar with an online tuner?
Unplugged, hold your phone close to the strings, because an electric guitar is quiet on its own. If it's too quiet to read, the tuner says so instead of guessing. Through an amp, use a clean sound at low volume with the phone near the speaker, and switch effects off so the tuner hears one plain note. GuitarTuna gives the same advice. Then go from the 6th string to the 1st. We've tested our tuner on synthetic tones, and as of October 2026 not yet on a real electric guitar.
What is GCEA tuning on a ukulele?
It's the standard tuning on most ukuleles: G4, C4, E4 and A4. The G is higher than the C beside it, which surprises people. That's called re-entrant tuning, and it's why the G string isn't the lowest one. If yours has a low G string, use Chromatic mode and aim for G3.
Are online tuners accurate?
On test tones, ours lands within a twentieth of a cent of the true pitch. With hiss mixed in at a quarter of the note's level, it stays within 2 cents. Your phone's microphone and clock add error we can't see: a clock off by a tenth of a percent moves every note by about 2 cents. So in tune here means within 5 cents, and a reading only counts once it holds still.
Does the tuner record me?
No. The microphone stays off until you press Start, on every visit, even if your browser remembers that you allowed it. While it's on, the tuner looks at a fraction of a second of sound at a time, works out the pitch and lets it go. Nothing is recorded, saved or sent. Press Stop, switch tabs or go three minutes without a note, and the tuner turns the microphone off.
How to tune a violin with an online tuner
Start with the A string. It's the one orchestras tune to first, and the others follow it. Then D, then G, then E.
Bow or pluck one open string and let it ring. If your violin has fine tuners, use those first, since a fine tuner moves the note a little at a time. Save the pegs for bigger changes. When the needle sits in the middle and the hint says in tune, move on to the next string.
Then go around once more. Tuning one string changes the pull on the bridge, and the strings you've already done can drift.
Using it as a guitar tuner or ukulele tuner
Switch the instrument to Guitar and the strings run E, A, D, G, B, E, from the 6th (low E, 82.41 Hz) to the 1st (high E, 329.63 Hz). Ukulele is G, C, E, A, with the G tuned above the C beside it. For drop D, a low-G ukulele, a bass, a viola or a cello, use Chromatic, which names any note and says whether it's flat or sharp.
Sources and last checked
- Standard tuning frequency, A4 = 440 Hz: ISO 16:1975, Acoustics - Standard tuning frequency (Standard musical pitch), section 2.1.
- String notes: Yamaha and Georgia State for violin, Roadie for standard guitar, and Fender for high-G ukulele. Tuning table checked October 7, 2026.
- Orchestras that tune higher, at 442 Hz: Tonhalle-Orchester Zurich on its concert A.
- Pitch detection: Philip McLeod and Geoff Wyvill, "A Smarter Way to Find Pitch", International Computer Music Conference, 2005.
- Microphone and audio behavior: W3C Media Capture and Streams (Candidate Recommendation Draft, October 9, 2025) and Web Audio API 1.1 (Working Draft, September 22, 2026).
- Error figures: measured by us on synthetic test tones at 44,100 and 48,000 samples per second.
- Last checked: October 7, 2026.
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Once the strings are in tune: set a tempo, press Start and play to a steady click.
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A teacher will check your tuning at the start of a lesson and show you how to use the pegs. Find violin teachers or guitar classes near you.
Strings drift between practices, so keep the tuner bookmarked for the next one.