Play or sing a note: its name, frequency, accidental and octave will be explained here.
Features of the online tuner
- ✓Automatic note detection — the YIN algorithm analyzes the audio in real time and identifies the note (C, D, E…) and its octave.
- ✓Cents meter — shows precisely whether you are flat or sharp, on a scale from −50¢ to +50¢.
- ✓Transposing instruments — support for B♭ clarinet, trumpet, English horn (UK: cor anglais), saxophone and more; it shows the written note and the sounding note at the same time.
- ✓Adjustable A4 reference — set the reference A, usually between 435 Hz and 450 Hz, to match any orchestra or tuning fork. (The tuner goes wider, from 390 Hz to 480 Hz, in case you need Baroque pitch.)
- ✓Reference notes — tap any note to hear a pure tone and tune by ear, with no microphone needed.
- ✓Letter note names — notes are shown as C, D, E, F, G, A, B. (The Spanish edition of the site shows the solfège names Do, Re, Mi, Fa, Sol, La, Si.)
- ✓Free, nothing to install — it runs in your browser on a phone, tablet or computer; no app needed.
A tuner for every instrument
Tuner for guitar
Standard guitar tuning (E–A–D–G–B–E) is the most common. Turn on the microphone, pluck an open string and adjust until the meter sits in the center. It also works for Drop D (strings 1 to 5 as usual, the 6th lowered to D) and other alternate tunings, as long as the note is within the chromatic range. The tuner detects any note automatically, so you do not need to select the string first.
Tuner for bass guitar
A standard 4-string bass is tuned E–A–D–G, one octave below the four lowest strings of the guitar. The tuner detects low frequencies down to 41 Hz (E1), so it covers 4-, 5- and 6-string basses. For the best results with very low notes, play near an external microphone or turn up the volume of the instrument.
Tuner for violin
The violin is tuned in fifths: G–D–A–E. The A string (A4 = 440 Hz) is the usual reference at the start of a rehearsal. The A4 reference can be adjusted, so you can match a Baroque ensemble (often 415 Hz) or an orchestra that tunes higher. Play each open string and adjust until the needle is centered.
Tuner for ukulele
A standard soprano ukulele is tuned G–C–E–A (re-entrant tuning: the G string is higher than the C string). The tuner covers that range and recognizes every string with no setup. Turn on the microphone, play each string separately and check that the needle settles on the right note.
Tuner for viola
The viola is tuned in fifths: C–G–D–A (C3–G3–D4–A4), a fifth below the violin. Play each open string and adjust until the tuner shows the right note centered at 0¢. The lowest string, C3 (about 131 Hz), needs the instrument close to the microphone because the frequency is low.
Tuner for cello
The cello is also tuned in fifths, C–G–D–A, but an octave below the viola (C2–G2–D3–A3). The low C2 (about 65 Hz) is hard for a phone’s built-in microphone to pick up. If the tuner does not respond, move the instrument closer or use an external microphone. The usual tuning reference in an orchestra is the A of the oboe.
Tuner for wind instruments
Flute, oboe, trumpet and clarinet can be tuned with the microphone in the same way as string instruments. For transposing instruments (B♭ clarinet, B♭ trumpet, English horn in F, E♭ alto saxophone…) turn on the “Transposing instrument” box: you will see the sounding note and the written note, as it appears in the score, at the same time.
How does this tuner work?
1. Turn on the microphone
Press “Start” in the tuner. Your browser will ask for temporary permission to use the microphone.
2. Play one note
Play a clear note. The screen shows which note it is (such as C or E) and which way the needle moves.
3. Adjust to the center
If the needle is on the left, the string is flat: tighten it. If it is on the right, the string is sharp: loosen it.
Understanding tuning
What is a cent?
The cent is the unit used to measure how far a note is from perfect tuning. A half step (semitone) is divided into 100 cents, so an octave has 1,200. Most listeners can hardly hear differences smaller than about 5 cents, so this tuner calls a note “in tune” when it is within ±5¢. The meter runs from −50¢ (half a half step flat) to +50¢ (half a half step sharp).
Frequency, hertz and pitch
The pitch of a sound depends on its frequency, measured in hertz (Hz): the more vibrations per second, the higher the sound. Every note has a specific frequency, and each octave up doubles it (A4 is 440 Hz; A5 is 880 Hz). The tuner converts the detected frequency into a note name and its deviation in cents. Octave numbers follow scientific pitch notation, in which middle C is C4.
A = 440 and calibration
The international standard sets A4 at 440 Hz, but it is not universal: many orchestras tune to 442 or 443 Hz to sound “brighter”, and early-music groups often use a Baroque pitch of 415 Hz. That is why the tuner lets you calibrate the A4 reference: set it before you begin so that it matches your ensemble.
Harmonics: why the fundamental matters
A real sound is not a single pure frequency. It is a fundamental (the one that gives the note its name) plus a series of higher harmonics that define the tone color. Simple tuners sometimes “jump” to a harmonic and show the wrong note. This tuner uses the YIN algorithm, which is robust against harmonics, to follow the fundamental even in rich or low sounds.
About accuracy
The real accuracy of any microphone tuner depends on the quality of the microphone, the background noise and how clean the sound is. Tested with exact tones, the detection engine (YIN) finds the frequency with an error of under about 1 cent across the musical range in clean-signal conditions; in real use, your microphone sets the limit. That is why there is a confidence indicator: if the signal is weak or noisy, the reading is not reliable, so move closer to the microphone and play a clear, sustained note. The stability history shows whether you hold the pitch or waver, which is very useful for voice and strings.
Notes for standard guitar
If you tune to 440 Hz (the usual reference), the goal is to get close to these frequencies when you play each open string.
Alternate guitar tunings
The tuner detects any note chromatically, so it works with all of these tunings without changing any setting.
| Tuning | 6th–5th–4th–3rd–2nd–1st | Common use |
|---|---|---|
| Standard | E–A–D–G–B–E | Every style |
| Drop D | D–A–D–G–B–E | Rock, metal, folk |
| Half step down | E♭–A♭–D♭–G♭–B♭–E♭ | Hendrix, Guns N' Roses |
| Open G | D–G–D–G–B–D | Blues, slide, Keith Richards |
| DADGAD | D–A–D–G–A–D | Celtic, folk, fingerstyle |
Frequently asked questions
Tuners by instrument
- Guitar tuner — E-A-D-G-B-E, Drop D, Open G
- Bass guitar tuner — E-A-D-G, with tips for 5 strings
- Violin tuner — G-D-A-E in fifths
- Viola tuner — C-G-D-A, a fifth below the violin
- Cello tuner — C-G-D-A, an octave below the viola
- Double bass tuner — E-A-D-G in fourths, low-note tips
- Ukulele tuner — G-C-E-A re-entrant; baritone D-G-B-E
- Mandolin tuner — G-D-A-E in paired strings
- Banjo tuner — Open G and 4- and 6-string tunings
- Harp tuner — Pedal and lever harps, concert pitch
- Flute tuner — Concert pitch, adjustable A4
- Piccolo tuner — Sounds an octave above written
- Oboe tuner — Concert pitch, the orchestra’s A
- English horn tuner — F transposing, written and sounding note
- Bassoon tuner — Concert pitch, from B♭1 up
- Contrabassoon tuner — Sounds an octave below written
- Clarinet tuner — B♭ transposing, written and sounding note
- Bass clarinet tuner — B♭ transposing, a ninth below written
- E♭ clarinet tuner — E♭ transposing, sounds a minor third higher
- Saxophone tuner — Soprano, alto, tenor and baritone transpositions
- Soprano Saxophone tuner — B♭ transposing, written and sounding note
- Alto Saxophone tuner — E♭ transposing, written and sounding note
- Tenor Saxophone tuner — B♭ transposing, written and sounding note
- Baritone Saxophone tuner — E♭ transposing, low notes from about 65 Hz
- Trumpet tuner — B♭ transposing, written and sounding note
- Flugelhorn tuner — B♭ transposing, warm conical tone
- French horn tuner — Horn in F, written and sounding note
- Trombone tuner — Tenor and bass trombone, slide positions
- Euphonium tuner — B♭ euphonium, bass clef or treble clef
- Tuba tuner — BB♭, CC, E♭ and F tubas, low-note tips
- Timpani tuner — Orchestral pedal timpani, ranges of 23-32 inch drums
Once your instrument is in tune, practice with a steady tempo using the online metronome. Good tuning and a firm tempo are the basis of any serious musical practice.