Frequency Detector
Detect sound and vocal frequencies in real-time using your microphone with live waveform analysis.
Advanced Audio Settings
Measure Sound Frequencies Accurately with the Frequency Detector
The Frequency Detector helps you measure the fundamental frequency (F0) of sounds in real time using your device’s microphone. Whether you’re singing a note, tuning an instrument, testing audio equipment, or analyzing room acoustics, the tool instantly displays the detected frequency in Hertz (Hz) while also translating it into the closest musical note.
Unlike traditional desktop audio software, this detector runs entirely inside your browser. After allowing microphone access, it continuously analyzes incoming audio using an autocorrelation algorithm paired with a low-pass filter to isolate the fundamental frequency while minimizing interference from overtones and background noise. Alongside the live frequency reading, you’ll also see a waveform visualizer and session statistics that update throughout your measurement.
How to Use the Frequency Detector
Getting started only takes a few steps:
- Select a preset that best matches your sound source (Standard, Deep Bass, or High Pitch).
- Click Start Frequency Detector.
- Allow microphone access when prompted by your browser.
- Speak, sing, whistle, or play an instrument near your microphone.
- Watch the live frequency display update in Hertz (Hz).
- Review the detected musical note, waveform, and session statistics.
- Use Copy Statistics if you want to save your session summary or Reset Stats to begin a fresh measurement.
If you’re new to pitch measurement, learning what frequency means in music can help you better understand your results.
Understanding Your Results
The detector provides several live measurements at the same time.
| Result | Description |
|---|---|
| Current Frequency | Displays the detected fundamental frequency in Hertz (Hz). |
| Musical Note | Converts the measured frequency into the nearest musical note with cent offset information. |
| Live Waveform | Visualizes the incoming audio signal in real time. |
| Session Minimum | Lowest detected frequency during the current session. |
| Session Average | Average frequency measured since the session started. |
| Session Maximum | Highest detected frequency during the session. |
For example, a frequency of 440 Hz corresponds to the musical note A4, commonly known as concert pitch. If you’d like to learn why this reference note is widely used, read What Is A4 Frequency?
Advanced Settings and Filter Presets
The Frequency Detector includes three filter presets that optimize detection for different sound sources.
- Standard Range – Suitable for most voices and musical instruments.
- Deep Bass – Optimized for bass guitars, low vocals, kick drums, and other low-frequency sounds.
- High Pitch – Better suited for flutes, violins, whistles, soprano voices, and similar high-frequency sources.
The Advanced Audio Settings also include two adjustable controls:
- Noise Gate (1%–40%) filters out quiet background sounds before analysis.
- Pitch Smoothing (0%–90%) reduces rapid fluctuations for a steadier frequency display during sustained notes.
These settings allow you to fine-tune measurements without changing the actual detected frequency.
If you’re comparing note names with measured frequencies, the Music Note Frequency Chart provides a useful reference.
Privacy and Accuracy
All audio processing happens locally within your browser. The tool never records or uploads microphone audio, so your measurements remain private on your device.
Because every microphone and recording environment is different, the detected frequency may fluctuate slightly with background noise, microphone quality, and playing technique. Using a quiet environment and holding steady notes generally produces the most stable results.
To better understand how pitch relates to measured frequency, you may also find Voice Pitch vs Frequency and What Is Hertz in Music? helpful.
Common Uses for a Frequency Detector
This tool is useful for many everyday audio tasks, including:
- Checking vocal pitch during singing practice.
- Measuring instrument tuning frequencies.
- Troubleshooting speakers and audio systems.
- Comparing room resonance and acoustic response.
- Identifying unknown musical notes.
- Monitoring frequency consistency during practice sessions.
For musicians learning ear training, reading How to Identify Musical Notes and Pitch vs Frequency can provide additional context for interpreting the detector’s output.
Frequently Asked Questions
Does the Frequency Detector record my microphone?
No. All processing occurs locally in your browser, and your audio is not recorded or transmitted to a server.
What is Hertz (Hz)?
Hertz measures how many complete sound-wave cycles occur every second. The detector displays this value as the primary measurement.
Why does the frequency keep changing?
Natural variations in your voice or instrument, background noise, and microphone sensitivity can all cause slight fluctuations. Increasing Pitch Smoothing can make the display steadier.
Can I use this tool to tune instruments?
Yes. It can help you monitor the frequency of played notes while tuning guitars, violins, ukuleles, pianos, and many other instruments.
What does the waveform show?
The waveform confirms that your microphone is receiving audio. It is a visual representation of the incoming sound signal and is separate from the frequency calculation.