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Free online cello tuner
A tuner that reads the cello's low C2, right in your browser.
The Jam Jam cello tuner listens through your microphone and tells you, in real time, which note is sounding and how far sharp or flat you are. The four strings are A3, D3, G2 and C2, in fifths, an octave below the viola. The low C2 sits around 65 Hz, low enough to confuse tuners built for guitar. In-tune zone at ±5 cents, cents to the unit, frequency to a tenth of a hertz.
How to tune a cello
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Allow the microphone
Open the tuner, pick Cello and grant mic access: the audio is analysed on your device, nothing is uploaded.
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Start with the A string
Bow the A string open: it targets A3. Get it green first, it is the easiest to read.
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Go down in fifths
Then D3, G2 and the low C2. The tuner locks onto the nearest string and shows the target.
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Let the low C settle
At 65 Hz the reading takes a moment. Bow steadily and wait for the needle to stop moving before adjusting the peg or fine tuner.
A tuner that goes down to the cello's C
C2 read as C2
Some tuners latch onto the octave harmonic on a low string. Jam Jam's cello preset expects the real C2.
Its own preset, not a transposed violin
A3, D3, G2, C2 are declared as the cello's targets; you never tune to a violin string an octave off.
Reference note in a cello voice
Every string plays its target note with a real cello timbre, so you can check a string by ear before touching the peg.
Auto, manual or chromatic
It locks the nearest string by itself; one tap freezes a string, another returns to auto. Chromatic mode covers anything outside the presets.
Why this cello tuner
- Standard C2, G2, D3, A3 in fifths
- ±5 cents to be in tune, cents to the unit and hertz to a tenth
- 100% free, in your browser, no sign-up and no ads
- Everything is computed on your side: nothing is uploaded
A single-purpose tuner site stops the moment you are in tune. Here the tuner is one tab among others in the Jam Jam notebook: import a song, transpose it, export it to PDF. Offline in the mobile app.
Open the tuner →More Jam Jam tools
Cello tuner FAQ
Is this cello tuner free?
Completely: no account, no ads, nothing to install. It all runs in your browser, and the microphone audio is analysed on the spot. It is never sent to a server.
Why does my low C read an octave too high?
That is a generic tuner picking the octave harmonic. Pick Cello in Jam Jam: the preset targets C2 at around 65 Hz, and locking the string with a tap keeps it there.
Pegs or fine tuners?
Pegs for large moves, fine tuners at the tailpiece for the last cents. Do the coarse move first, then bring the needle into the green band with the fine tuner.