Free Online Violin Tuner
Standard GDAE plus three fiddle scordaturas. A4 reference selector for orchestras that tune to 442 or 443 Hz. Bow or pluck a string — the tuner shows the detected note, frequency in Hz, and cents-offset.
Reference Tones
Tap a string to hear it bowed. Tune by ear against the reference if you don't want to enable the microphone.
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How to use this tuner
1. Confirm the A4 reference. 440 Hz is the international standard and what almost every American and British orchestra uses. If you are about to play in a German or Austrian orchestra, switch to 442. Russian and some Eastern European orchestras tune to 443. For solo practice the safe default is 440.
2. Pick the tuning. Standard GDAE for classical, jazz, and most playing. AEAE cross-tuning, GDAD, and DDAD are fiddle scordaturas for specific old-time and Irish trad styles.
3. Enable the microphone. Audio is processed locally in your browser — nothing is uploaded.
4. Tune the A string first. The convention is to tune A against the reference, then tune the other three strings to it. Bow a long sustained note on the A string — the bowed note gives the tuner a clean, sustained signal that's easy to read. The display shows the detected note (e.g., "A4"), the actual frequency, and how many cents you are sharp or flat.
5. Always tune up to the note. If you are flat, tune up to the target. If you are sharp, tune below the target and then come back up. Coming up to pitch from below is more stable on a violin — the pegs and the string both settle better that way.
6. Use the fine tuners for small adjustments. If you are within about 10 cents of the target, use the fine tuners on the tailpiece rather than the pegs. The pegs are friction-fit and can slip; the fine tuners are mechanically geared and let you adjust by a cent or two at a time.
Perfect fifths and why violinists tune by ear
The violin is tuned in perfect fifths — a frequency ratio of exactly 3:2 between each pair of adjacent strings. G to D is a perfect fifth; D to A is a perfect fifth; A to E is a perfect fifth. This is the same interval as the first two notes of "Twinkle, Twinkle, Little Star," and it is the most consonant interval after the octave — the two notes blend so smoothly that beats between them are easy to hear.
This is why professional violinists usually tune by ear rather than electronically. Bow two adjacent open strings simultaneously — say A and D. If they are in perfect-fifth tune, the combined sound is smooth and steady. If one is even a few cents off, you hear distinct beats — a slow throbbing that gets faster as the pitch moves further from true. Adjusting the lower string until the beats disappear is more precise than reading a needle. Trained ears can hear beats down to about 1 cent.
An electronic tuner is most useful for setting the A string against an external reference, and as a check that the other three strings haven't drifted out of true. After that, double-stops at the fifths are the more refined method. Most violinists use both — tuner for the A, then double-stops for D, G, and E.
The A=440 standard, and why some orchestras ignore it
For most of musical history there was no standard tuning. Different cities, different decades, and different instrument makers all used different pitch references. Bach's Leipzig used roughly A=415 Hz (a whole semitone below modern pitch). Mozart's Vienna was somewhere around A=421-430. By the late 19th century pitch had crept upward, and Paris in 1858 settled on A=435 as an official standard, while London opera houses sometimes pushed up to A=455.
The modern A=440 Hz standard was set at an international tuning conference in London in May 1939, with representatives from American, British, French, German, Italian and Dutch broadcasting and instrument-making organisations. It was formalised by the International Organization for Standardization in 1955 as ISO 16:1975. Most American orchestras, British orchestras, Hollywood film scores and almost all popular music recordings use it.
But many Continental European orchestras tune higher. The Berlin Philharmonic and the Vienna Philharmonic tune to A=443. Most German, Austrian and Czech orchestras tune to A=442. Some Russian orchestras tune to A=443 or 444. The reason is mostly aesthetic — bowed strings sound brighter and more "alive" at higher tensions, and the soloists and audiences in those traditions prefer that brightness. A solo violinist crossing between American and European orchestras retunes between rehearsals. This tuner supports all four references; switch the A4 button at the top to match wherever you are playing.
The fiddle scordaturas
AEAE — cross-tuning, "high bass." Both the G and D strings are tuned up a whole step to A and E, matching the existing top two strings. The result is two pairs of strings tuned in unison an octave apart. Drone-heavy and resonant — used in Appalachian old-time breakdowns ("Bonaparte's Retreat," "Black Mountain Rag," "Tom and Jerry"). The tuning makes any open A or E ring across multiple strings simultaneously, producing a full, hypnotic sound under a melody. Standard practice in southern Appalachian fiddle since at least the 19th century.
GDAD — Irish trad fiddle scordatura. Only the top E is changed — down a whole step to D. Allows open-string drones against any melody in D major, the most common Irish trad key. Used in some Donegal and Scottish fiddle styles for specific repertoire. Less common than the standard GDAE in Irish trad overall, but the players who use it use it consistently.
DDAD — open D modal tuning. The G drops a perfect fourth to D, and the high E drops a whole step to D. Three of the four open strings are D, creating a permanent open-fifth drone (D-A) and an open-octave drone (D-D). Used in old-time modal fiddle for tunes like "Cluck Old Hen," "Shady Grove," "Bonaparte's Retreat" (cross-tuned versions). The constant D drone makes minor and modal melodies sound naturally haunting.
All three scordaturas are well-documented in published fiddle literature and on commercial recordings. If you are learning from a specific recording, check whether the fiddler is in scordatura — much old-time and Irish trad fiddle is, and a tune in standard tuning will sound thin and wrong if the source recording was cross-tuned.
Violin tuning reference table
| Tuning | Strings (4 → 1) | Frequencies at A=440 (Hz) | Used for |
|---|---|---|---|
| Standard GDAE | G3 D4 A4 E5 | 196.00 · 293.66 · 440.00 · 659.26 | Classical, jazz, almost all repertoire |
| AEAE cross-tuning | A3 E4 A4 E5 | 220.00 · 329.63 · 440.00 · 659.26 | Old-time Appalachian fiddle, breakdowns |
| GDAD | G3 D4 A4 D5 | 196.00 · 293.66 · 440.00 · 587.33 | Irish trad, Donegal fiddle scordatura |
| DDAD | D3 D4 A4 D5 | 146.83 · 293.66 · 440.00 · 587.33 | Old-time modal fiddle, drone-heavy tunes |
| ADAE (low bass) | A2 D4 A4 E5 | 110.00 · 293.66 · 440.00 · 659.26 | Rare old-time scordatura, "drone bass" |
| Baroque tuning | GDAE at A=415 | 184.99 · 277.18 · 415.00 · 622.25 | Bach, Telemann, Vivaldi on period instruments |
Highlighted row is the modern standard. Baroque tuning (A=415) sounds a whole semitone lower than modern pitch — a Bach concerto played at 415 sounds in a different key than the same notation played at 440. Period-instrument ensembles tune this way for historical authenticity.
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Related instruments — different tunings
Viola — slightly larger than a violin. Tuned a perfect fifth lower: CGDA (C3, G3, D4, A4). The bottom string is C, the top is A. Plays the alto range in string quartets and orchestras.
Cello — much larger, played seated between the knees. Same CGDA pattern as viola but a full octave lower: C2, G2, D3, A3.
Double bass — the largest member of the violin family. Tuned in fourths (not fifths) — E1, A1, D2, G2 — the same as the bottom four strings of a bass guitar. Played upright with a bow or pizzicato.
Mandolin — not a bowed instrument, but tuned identically to a violin: GDAE in pairs of strings (8 strings in 4 courses). A fiddler can pick up a mandolin and play with familiar fingerings.
Continue exploring
Sources & technical notes
- International Organization for Standardization, ISO 16:1975 — Acoustics — Standard tuning frequency — the international codification of A4 = 440 Hz, from the 1939 London tuning conference.
- David Boyden, The History of Violin Playing from Its Origins to 1761 (Oxford University Press, 1965) — the foundational scholarly history of the violin and Baroque tuning practices.
- Robin Stowell (ed.), The Cambridge Companion to the Violin (Cambridge University Press, 1992) — chapters on contemporary technique, scordatura, and historical pitch.
- Alan Jabbour, American Fiddle Tunes from the Archive of Folk Culture (Library of Congress, 1971, multiple revisions) — the standard reference for old-time American fiddle traditions, including the AEAE cross-tuning and DDAD modal scordaturas documented across Appalachian recordings.
- Brendán Breathnach, Folk Music and Dances of Ireland (Talbot Press, 1971) — the standard Irish-trad music reference, including GDAD and other regional scordaturas.
- The pitch detector uses the YIN method described in Alain de Cheveigné and Hideki Kawahara, "YIN, a fundamental frequency estimator for speech and music", Journal of the Acoustical Society of America 111(4), 2002, with an octave-down guard that prefers the higher true fundamental when a sub-period is an equally-deep dip.
- Bruce Haynes, A History of Performing Pitch: The Story of "A" (Scarecrow Press, 2002) — definitive scholarly source on the history of pitch standards from the 16th century to modern day, including the variations between continental orchestras.
Four strings, perfect fifths, no frets. Tuned by ear since 1556. Tune the A first.