What is a noise meter?
A noise meter measures the strength of sound captured by a microphone. This free browser tool provides a live estimate of microphone signal level so you can observe changes in room noise, speech, music and other sounds.
How the Noise Meter works
The tool requests microphone access and connects the stream to the Web Audio API. An AnalyserNode reads the audio waveform and calculates a root-mean-square (RMS) amplitude. That value is converted to a normalized relative scale from 0 to 100 for the visual meter.
What can you use it for?
- Checking whether a microphone is receiving sound
- Comparing quiet and noisy environments
- Testing microphone input before a call or recording
- Observing speech and room noise levels
- Quick browser-based audio experiments
Is the displayed level a real decibel reading?
No. Microphone hardware, operating-system gain, browser processing and device calibration all affect the captured signal. A browser application generally cannot turn raw microphone amplitude into a trustworthy absolute dB SPL measurement without calibration. The scale on this page is therefore intentionally described as an estimated relative level.
How to use the Noise Meter
- Press Start Microphone.
- Allow microphone access when your browser asks.
- Speak, clap, play music or observe the room's background noise.
- Watch the live meter, peak and recent average.
- Press Stop when finished.
Privacy
Microphone permission is requested only after you press the start button. The audio stream is analyzed locally using the Web Audio API. This page does not need to upload or record your microphone audio, and no account is required.
Frequently asked questions
Is this a free noise meter?
Yes. It is a free browser-based microphone level tool.
Does it record my microphone?
No recording is needed. The tool analyzes live microphone samples for the meter.
Why is it not an exact dB meter?
Because the microphone's electrical signal is not automatically calibrated to sound pressure level. Device gain and hardware sensitivity differ between microphones.
Can I measure room noise with it?
Yes, as a relative indicator. For certified or accurate acoustic measurements, use a calibrated sound level meter.