Voice Pitch Analyzer
FREE
Analyze vocal pitch in real time from your microphone. See note names, Hz, cents deviation, stability, and a live pitch curve—free in your browser.
Current
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Hertz (Hz)
Min Hz
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Average
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Max Hz
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Allow microphone access to measure live frequency in Hz.
Common reference frequencies
- Low E (guitar)
- Middle C (C4)
- Concert A (A4)
- Standard test tone
Help Us Improve
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Online frequency detector
Measure sound frequency in real time from your microphone. See live Hz, min, max, and average with a waveform view—free in your browser.
What is an online frequency detector?
An online frequency detector measures how fast sound waves vibrate each second and shows the result in Hertz (Hz). This hosted Hz meter uses your microphone and autocorrelation to estimate the fundamental frequency of singing, humming, speech tones, whistles, or steady instrument notes. Unlike a chromatic tuner that rounds to note names, this frequency meter focuses on raw Hz readings with two decimal places—useful for tuning checks, acoustics demos, and ear training alongside tools like /sound-memory-game.
Frequency detector features
Real-time Hz measurement with session stats and waveform preview.
Live Hz readout
Current frequency updates continuously while detection runs—no upload step.
Min, average, and max
Session stats track the lowest, mean, and highest Hz captured during a run.
Oscilloscope waveform
See the incoming audio wave so you can spot steady tones versus noisy input.
Copy Hz values
One-click copy for the live reading or common reference frequencies.
Autocorrelation engine
Estimates fundamental frequency (F0) from the microphone time-domain signal.
Browser-only processing
Audio stays on your device—nothing is recorded or sent to a server.
How to use the Hz detector
Start measuring frequency in a few seconds.
Start detection
Click Start detection and allow microphone access when prompted.
Produce a steady sound
Sing one note, hum, whistle, or play a single instrument pitch toward the mic.
Read and copy Hz
Watch the live Hertz value and session min, average, and max. Copy Hz when you need the number elsewhere.
Stop when finished
Click Stop detection to release the microphone and reset the session stats.
Tips for accurate frequency measurement
Get cleaner Hz readings from the sound frequency meter.
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Use a quiet room
Fans, traffic, and room hum raise the noise floor and can hide the tone you want.
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Hold one pitch
The detector works best on steady tones—not fast melodies or percussive hits.
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Stay close to the mic
A consistent distance helps level stay above the silence gate.
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Disable aggressive processing
This tool requests raw-ish mic input; system “voice enhancement” can skew readings.
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Compare with references
Use the built-in 440 Hz and middle C references when calibrating by ear.
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Practice recall on /sound-memory-game
After measuring Hz, train pitch memory with the five-round frequency recall game.
Sources & References
Authoritative references on frequency detection, fundamental frequency estimation, and the Web Audio technology this tool uses.
“The fundamental frequency, often referred to simply as the fundamental, is the lowest frequency of a periodic waveform. In music, the fundamental determines the perceived pitch of a note.”
Fundamental frequency (F0) estimation: This Hz detector estimates the fundamental frequency of live microphone input using a time-domain autocorrelation approach, displaying the result as raw Hertz with two decimal places. en.wikipedia.org/wiki/Fundamental_frequency
“Autocorrelation is the correlation of a signal with a delayed copy of itself as a function of delay. It is widely used in pitch detection to find the period of a periodic signal.”
Autocorrelation-based pitch detection: The tool applies autocorrelation on short audio frames from the microphone to identify the repeating period of the waveform, from which the frequency in Hz is computed. en.wikipedia.org/wiki/Autocorrelation
“The hertz is the unit of frequency in the International System of Units, equivalent to one event (or cycle) per second.”
Hertz — unit of frequency: All measurements are displayed in Hertz (Hz), representing the number of vibration cycles per second. Common reference: A4 = 440 Hz. en.wikipedia.org/wiki/Hertz
“The MediaDevices.getUserMedia() method prompts the user for permission to use a media input which produces a MediaStream containing tracks of the requested types.”
MediaDevices.getUserMedia (microphone access): Live microphone access is requested via the getUserMedia API. Audio is processed entirely in the browser using Web Audio API — nothing is uploaded or recorded on a server. developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia
Frequently Asked Questions
Quick answers about this tool—open a question to read more.