Compare relative loudness on one device
Measure the same spot twice in a row and see whether the environment has become noisier.
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Guide
The noise meter calls getUserMedia after you click and asks for the microphone, explicitly switching off echoCancellation, noiseSuppression and autoGainControl. The audio goes only into a Web Audio AnalyserNode and never to the speakers, which avoids feedback; the page computes RMS and an FFT spectrum and maps dBFS plus 100 roughly onto a 0–120 dB scale.
Updated 2026-09-271 min read
The implementation computes 20*log10(RMS) to get the digital audio dBFS and adds a fixed offset of 100; that is not a true sound pressure level in dB SPL measured with a calibrated microphone.
Measure the same spot twice in a row and see whether the environment has become noisier.
Look at the 48 bars to see how much of the sound is low-frequency rumble and how much is high-frequency noise.
Walk around while measuring and find where in the room the reading is clearly highest.
No — the current code has no microphone calibration and the mapping is only rough.
Microphone data is analysed in real time in the current browser; nothing is uploaded and nothing is recorded, and the media tracks are closed when you stop.
Updated 2026-09-27
Estimate ambient decibels with the microphone and show the noise level (indicative only)
This browser cannot capture audio from a microphone; please use a modern browser.
Disclaimer:Microphones in phones and computers are not acoustically calibrated and their sensitivity varies widely, so the decibel values shown here are a rough estimate,for reference only — they cannot replace a professional sound level meter. For noise enforcement or occupational health assessments, use professional equipment that meets metrology standards.