1. Reference tones — tune by ear
Tap a string to hear its target pitch on a loop. Tune your string until it matches, then tap again to stop.
2. Live tuner — use your microphone
Bow or pluck a string near your mic. We'll detect the pitch and show exactly how sharp or flat you are, updated live.
All four strings
Reference tones for C2, G2, D3 and A3 — standard cello tuning, ready to play on a loop.
Real-time pitch detection
Your microphone feeds a live autocorrelation algorithm that tracks pitch as you play.
Cent-accurate gauge
See exactly how sharp or flat you are in cents, not just a vague "close enough."
Fully private
Pitch detection runs locally in your browser. Nothing is recorded or uploaded.
Works everywhere
No app, no install. Works in any modern browser on desktop or mobile.
Standard Cello Tuning Notes & Frequencies (C-G-D-A)
A cello has four strings, tuned a fifth apart. From the thickest (lowest) string to the thinnest (highest), here's exactly what each one should sound like and the frequency it's tuned to:
| String | Note | Frequency | What to listen for |
|---|---|---|---|
| 1st | C2 | 65.41 Hz | The thickest string and the lowest, deepest note on the cello — almost a rumble. |
| 2nd | G2 | 98.00 Hz | A fifth above the C string — still low, but noticeably warmer and less boomy. |
| 3rd | D3 | 146.83 Hz | The middle string, closest to a comfortable singing pitch for most voices. |
| 4th | A3 | 220.00 Hz | The thinnest string and the brightest, highest-pitched of the four. |
Tip: each string is tuned a perfect fifth above the one before it (C→G→D→A), which is why they blend so well when played together. These frequencies use concert pitch, where A4 = 440 Hz.
How to tune your cello
Pick your method
Use reference tones if you like tuning by ear, or the microphone tuner for a visual readout.
Play the string
Bow or pluck the string you're tuning, close to your device's microphone if using the live tuner.
Adjust the peg
Turn the peg or fine tuner slowly — tighten to raise pitch (sharp), loosen to lower it (flat).
Confirm in tune
Match the reference tone by ear, or watch the needle settle in the green zone on the gauge.
Frequently asked questions
What notes are cello strings tuned to?
A standard cello has four strings tuned in fifths: C2 (65.41 Hz), G2 (98.00 Hz), D3 (146.83 Hz), and A3 (220.00 Hz), from lowest to highest. This tuner covers all four.
Should I tune by ear or use the microphone tuner?
Either works. Reference tones are great if you're used to tuning by ear and just need a pitch to match. The microphone tuner is faster if you'd rather see exactly how sharp or flat you are in cents, especially useful for beginners still training their ear.
How accurate is the pitch detection?
It analyzes your microphone input in real time and estimates pitch to within a few cents in a reasonably quiet room. Background noise, a very quiet bow stroke, or other instruments playing nearby can reduce accuracy, so it works best with just your cello near the mic.
Does this work for 4/4, 3/4, or smaller cellos?
Yes. Cello size affects the instrument's scale length and feel, not the pitch its strings are tuned to — a 3/4 or 1/2 size cello uses the same C2-G2-D3-A3 tuning as a full-size instrument.
Can I use this for a 5-string cello or alternate tunings?
This tuner covers the standard four-string C-G-D-A tuning. A 5-string cello's extra string (usually a high E) or other alternate tunings aren't included, but you can still use the microphone tuner's frequency readout as a general pitch reference.
Is the cello tuner free, and does it store any audio?
Yes, it's completely free with no sign-up. The microphone tuner processes sound entirely in your browser using the Web Audio API — nothing is recorded, uploaded, or stored anywhere.