Decibel Meter
Measure ambient noise levels in real-time using your phone's microphone, with noise level reference chart.
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Click "Start Measuring" to request microphone permission
- Click "Start Measuring" — your browser will request microphone permission.
- After granting permission, the meter will display real-time ambient noise in decibels.
- Watch the gauge: green is quiet (<40dB), yellow is moderate (40-70dB), orange is loud (70-85dB), red is very loud (>85dB).
- Click "Stop Measuring" when done — the microphone will be automatically released.
This tool uses the Web Audio API to capture audio from your phone's microphone via getUserMedia.
An AnalyserNode processes the audio waveform data, calculates the RMS (root mean square) amplitude, and converts it to decibels (dB).
The displayed dB value is smoothed to reduce jitter. Due to differences in phone microphones, values are approximate and for reference only.
- Accuracy varies between devices — results are approximate.
- Not a substitute for professional sound level meters for regulatory or occupational safety purposes.
- Avoid touching or covering the microphone during measurement.
- Prolonged exposure to noise above 85dB may cause hearing damage.
How accurate are the measurements?
Phone microphone dB readings are approximate, with potential ±5-10dB deviation compared to professional meters. Suitable for general noise awareness but not for precision measurements or regulatory compliance.
Why does the value keep jumping?
Ambient noise naturally fluctuates, and microphone sensitivity varies. Some fluctuation is normal. The tool applies smoothing to reduce excessive jumping.
Is my audio being recorded?
No. All audio data is processed locally in your browser in real-time. Nothing is recorded, stored, or sent to any server.
Why are readings low in some environments?
Phone microphones are typically optimized for voice frequencies and may be less sensitive to low-frequency (e.g., traffic) or high-frequency sounds, leading to lower readings.