It accesses your device's microphone (with permission) and captures live audio. The tool then applies a mathematical autocorrelation algorithm to detect the fundamental frequency of your voice. This frequency is mapped to the nearest musical note and the deviation is shown in cents (hundredths of a semitone). The result is displayed on a tuner‑like gauge and a scrolling history chart.

Frequency is a physical measurement of sound vibrations per second, expressed in Hertz (Hz). Pitch is the perceptual correlate – how high or low a note sounds. In music, pitch is often labeled with note names (like A4, C5). Our tool measures frequency and translates it to the corresponding musical pitch.

A4 (the A above middle C) tuned to 440 Hz is the international standard pitch reference. Most modern music uses this reference. You can change the reference frequency in the tool if you need historical tuning (e.g., 432 Hz) or orchestral variations (442 Hz, 443 Hz).

Possible reasons:

• Microphone access was denied – please allow it in your browser settings.
• Your microphone is not connected or selected correctly.
• Background noise is too loud – try to reduce ambient sounds.
• Your voice is too soft or too far from the mic.
• Extremely low or high notes may be outside the detectable range (typically ~80 Hz to 1000 Hz).

Under ideal conditions (clear voice, minimal noise, good microphone) accuracy can be within ±2 cents. The autocorrelation algorithm is optimized for monophonic signals like vocals. Polyphonic sources (multiple notes together) cannot be analyzed reliably.

Yes, after the page is fully loaded, the audio processing runs entirely in your browser using the Web Audio API. No data is sent to any server. You can use it offline as long as the page is cached.