Online Tuner (Guitar, Ukulele, Violin, Chromatic)

About the Online Tuner (Guitar, Ukulele, Violin, Chromatic)

Press Start tuner, allow the microphone and play one note: the tuner shows the note and octave, how many cents it is sharp or flat, and a needle that turns green when you are in tune. Use it chromatically for any instrument or voice, or pick a preset — guitar (standard, drop D and other tunings), bass, ukulele, violin, viola, cello or mandolin — to see which string you are playing and press a string to hear its reference note.

The reference pitch A4 is 440 Hz by default and can be set anywhere from 400 to 480 Hz (for example 415 for baroque, 442 for many orchestras). The Indian classical mode shows the swara — Sa, Re, Ga, Ma, Pa, Dha, Ni with komal and tivra notes and the saptak — relative to the Sa you choose. The sound is analysed on your device and never recorded or uploaded.

Common uses

• Tuning a guitar, bass, ukulele or bowed string instrument before practice or a performance.
• Checking the pitch of your singing, or a harmonium, keyboard or flute.
• Tuning to a reference other than 440 Hz for an orchestra, choir or baroque ensemble.
• Riyaz in Indian classical music: checking swaras against your Sa.

How it detects the pitch

The tuner reads about 85–93 milliseconds of sound at a time (4,096 samples, depending on your device’s sample rate) and finds its pitch with the McLeod Pitch Method (P. McLeod and G. Wyvill, A smarter way to find pitch, International Computer Music Conference 2005), using the open-source pitchy library. The method compares the sound with itself shifted in time (a normalised square difference function); the shift at which it lines up best is one period of the note, and the frequency is the sample rate divided by that period. It is reliable for plucked and bowed strings and the voice, follows the fundamental even when overtones are stronger, and gives a clarity score, so noise and chords are ignored instead of showing a random note.

The page asks the browser to switch off echo cancellation, noise suppression and automatic gain, which would otherwise distort the sound. Readings are steadied over a few frames, and a sudden jump of more than half a semitone has to repeat before the display follows it.

Notes, cents and the reference pitch

Notes follow 12-tone equal temperament: f = A4 × 2^((n − 69) ÷ 12), where n is the MIDI note number (A4 = 69, middle C = C4 = 60). A cent is a hundredth of a semitone: cents = 1200 × log2(f ÷ target). Most listeners cannot hear a difference of a few cents, so the needle turns green within ±5 cents.

The international standard ISO 16 sets A4 at 440 Hz. Orchestras in continental Europe often tune between 440 and 444 Hz, and period-instrument ensembles use 415 Hz for baroque pitch; set Reference A4 to match the group you play with.

Instrument presets

• Guitar: standard E2 A2 D3 G3 B3 E4 (82.41 to 329.63 Hz), drop D, half step down, open G, open D and DADGAD
• Bass guitar: E1 A1 D2 G2, or B0 E1 A1 D2 G2 for five strings
• Ukulele: G4 C4 E4 A4 (high, re-entrant G), low G, and baritone D3 G3 B3 E4
• Violin G3 D4 A4 E5 · Viola C3 G3 D4 A4 · Cello C2 G2 D3 A3 · Mandolin G3 D4 A4 E5 (pairs of strings)

In a preset the tuner listens only from half an octave below the lowest string to two octaves above the highest, which avoids octave mistakes, and highlights the string closest to what you play.

Indian classical mode (swaras)

Choose your Sa (tonic) — a note and octave, or press Set Sa while you sing or play it. The display then names the swara you produce: Sa, komal Re, Re, komal Ga, Ga, Ma, tivra Ma, Pa, komal Dha, Dha, komal Ni and Ni, with the saptak: mandra (the octave below your Sa), madhya (from Sa upward) or taar (the octave above).

Equal temperament places the swaras every 100 cents, like a harmonium. Just intonation measures against one common set of ratios instead: Sa 1/1, komal Re 16/15, Re 9/8, komal Ga 6/5, Ga 5/4, Ma 4/3, tivra Ma 45/32, Pa 3/2, komal Dha 8/5, Dha 5/3, komal Ni 16/9, Ni 15/8. In practice the exact pitch of a swara depends on the raga and the musician, so use the cents as a guide, not a rule.

Tips for accurate tuning

• Play one string at a time and let it ring; mute the others.
• Tune up to the note: if you are sharp, go a little below and come back up — the string holds its tuning better.
• Hold the microphone 10–30 cm from the instrument and keep the room quiet; fans and other instruments confuse any tuner.
• For the lowest bass notes, play firmly and let the note sustain for a second.

Limitations

• One note at a time: chords and several instruments at once cannot be tuned.
• Very high notes (above about 2,000 Hz) and very short, percussive sounds are read less precisely.
• Some phones and Bluetooth headsets process the microphone sound in ways the browser cannot switch off; a wired or built-in microphone works best.
• The microphone needs a secure (https) page and your permission; nothing is recorded.

Privacy

The microphone sound is analysed in your browser, frame by frame, and thrown away immediately; nothing is recorded, stored or uploaded. Your settings (reference pitch, mode, Sa) are remembered on this device only.