A decibel meter measures the loudness of sound around you in real time. This online decibel meter reads from your microphone and shows a relative SPL value scaled to the familiar 30–130 dB range — useful for quick comparisons of room noise, traffic, or appliance loudness, but not a replacement for a calibrated meter.
Why "relative"?
Browsers don't expose absolute microphone sensitivity, so the numbers are an approximation against typical built-in laptop and phone mics. If you need certified readings (for regulation, court, or workplace compliance), use a Class 1 or Class 2 SPL meter.
Hearing-safe levels
- Below 70 dB — safe for unlimited exposure.
- 85 dB — OSHA limit for 8 hours.
- 100 dB — safe for ~15 minutes per day.
- 120 dB+ — can cause immediate hearing damage.
Frequently asked questions
Why does the decibel meter read 30 dB in a quiet room?
30 dB is roughly a quiet bedroom or whisper — the floor of what most home microphones can resolve. Anything truly silent reads as 30 dB because the mic itself has self-noise.
Can I use this decibel meter to file a noise complaint?
No. Browser-based readings aren't legally admissible. Use them as a first-pass indicator before deciding whether to bring in someone with a certified meter.
Why does the reading jump around so much?
Sound pressure varies fast. The peak, average, min, and max cards summarise the spread. Watch the running average for a stable picture of the room rather than a single instant value.
Is anything recorded or uploaded?
No. The decibel meter processes audio locally in your browser. Nothing is uploaded or stored.