Free tool · Tuner
Free online tuner for violin, viola, cello, and bass
Bow a string and the arc guides you in. No account, no download, and the microphone audio never leaves your device.
Tap Start tuning below, then bow any string.
Hear each open string
Train your intonation ear
How to tune, step by step
Choose your instrument
Select violin, viola, cello, or double bass so the tuner knows which open strings to expect.
Allow microphone access
Your browser will ask for permission. The audio is analysed on your device and is never uploaded.
Start with the A string
Bow one string slowly and steadily. The tuner shows which note it hears and how many cents sharp or flat you are.
Make small, careful adjustments
Use a fine tuner, if fitted, for small pitch corrections. If you are new to tuning, ask a teacher for help with pegs or large pitch changes. Never force a stiff peg or a fine tuner that has reached its limit; double basses usually use geared tuning machines.
Go around a second time
Tuning one string changes the tension on the others, so it is worth checking all four again. Finish by listening to adjacent strings together.
The full detail, pegs versus fine tuners, tuning by fifths, and what to do when a string will not hold, is in the complete tuning guide.
Try it: tune a cello A string
- Choose Cello and A = 440 Hz, unless your teacher or ensemble uses another reference. The open cello A string is A3, approximately 220 Hz; the 440 Hz setting names A4, one octave higher.
- Tap the A reference-tone button and listen. Stop the reference tone before taking a microphone reading so the tuner hears your instrument.
- Bow the open A string without a left-hand finger. A reading of −10 cents means slightly flat; +10 cents means slightly sharp. Confirm that the detected note is A3 before making any adjustment.
- Make a small correction with the fine tuner if one is fitted, then sound the string again. Aim for a steady reading near zero rather than chasing every flicker. Check D3, G2, and C2, then return to A3.
Avoid these common tuning mistakes
A tuner can detect an overtone or a nearby sound. Do not tighten a string simply because the screen shows an unexpected octave. Stop, compare with the reference tone, and ask your teacher if the pitch is far from the target. Keep the bow clear of neighbouring strings. If microphone access is unavailable, the reference tones still let you compare by ear.
Next, try the beginner cello lessons, or learn how intonation differs from open-string tuning.
Standard tunings
| Instrument | Strings, low to high | Interval |
|---|---|---|
| Violin | G3 · D4 · A4 · E5 | Perfect fifths |
| Viola | C3 · G3 · D4 · A4 | Perfect fifths |
| Cello | C2 · G2 · D3 · A3 | Perfect fifths |
| Double bass | E1 · A1 · D2 · G2 | Perfect fourths |
Tuner questions
- Is this tuner free?
- Yes, completely, no account, no download, and no advertising. It runs in your browser and works on phones, tablets, and computers.
- Does the tuner record my playing?
- No. Pitch detection runs entirely in your browser using the Web Audio API. The microphone audio is analysed on your device and never uploaded to a server or stored anywhere.
- What are the standard tunings?
- Violin is G3–D4–A4–E5, viola is C3–G3–D4–A4, cello is C2–G2–D3–A3, and double bass is E1–A1–D2–G2. The first three are tuned in perfect fifths; the double bass is tuned in fourths.
- Can I tune to 442 Hz or baroque pitch?
- Yes. The reference pitch can be set to A = 440 Hz for standard tuning, 442 Hz as used by many orchestras, or 415 Hz for baroque repertoire, which is roughly a half step lower.
- Why does my tuner reading jump around?
- Usually background noise or a bow that is not producing a steady tone. Use a steady bow stroke with a consistent contact point between bridge and fingerboard, keep the room quiet, and let the note settle for a second before reading the display.
Ready for a short guided lesson?
Five lessons on your instrument and five in theory. Free to keep, no card. This tuner stays free either way.
Start free