Online Cello Tuner
Precise low-frequency tuning for cello — standard C G D A plus Bach's 5th Suite scordatura.
Tap the mic and play a string
How to tune a cello online
Tap the microphone button and allow browser access — nothing is recorded or uploaded. Bow one string at a time close to your device's microphone and let it ring. The low C string needs a moment longer to register clearly, so bow steadily and be patient.
Standard cello tuning
Standard cello tuning, from lowest to highest string, is C G D A, each a perfect fifth apart — the same pitches as a viola, one octave lower. CleanTune also supports the Bach 5th Suite scordatura (C G D G), where the top A string is tuned down to G, as called for in Bach's Cello Suite No. 5. Switch between them with the tuning selector above.
What a wolf tone is, and why it can confuse a tuner
Some cellos have a "wolf tone" — usually around F or F# on the G string — where the body's resonant frequency clashes with the string's vibration, causing a warbling, unstable pitch. If a specific note refuses to read cleanly on the tuner no matter how carefully you bow it, you may be hitting your instrument's wolf tone rather than doing anything wrong; a wolf eliminator clipped to the string after the bridge is the standard fix.
Get close to the mic
Low frequencies carry less energy — bowing near your device's microphone improves detection accuracy.
Use fine tuners for small changes
If your cello has fine tuners, use them for subtle corrections — pegs are better reserved for larger adjustments.
Reduce background noise
Rumble and hum interfere with low-frequency detection more than with higher strings — find a quiet room.
Frequently asked questions
What is standard cello tuning?
Standard cello tuning, from lowest to highest string, is C G D A, tuned in perfect fifths — one octave below viola.
What is the Bach 5th Suite scordatura?
In his Cello Suite No. 5, Bach calls for the top A string to be tuned down to G, giving C G D G. This scordatura changes the instrument's resonance for that piece.
Why is my low C string hard to tune?
Very low frequencies carry less energy and can be harder for any microphone to pick up cleanly. Bow steadily close to your device's microphone in a quiet room for the most accurate reading.
Why does one note on my cello sound unstable no matter how I bow it?
That's likely a wolf tone, caused by the cello body resonating in conflict with the string. It's a known quirk of the instrument's construction, not a tuning error, and a wolf eliminator on the string after the bridge usually resolves it.