Sound Meter

This is a free, browser-based sound level meter that uses your device's microphone to measure ambient noise in decibels (dB) — no app download, no sign-up, nothing to install. You open it, hit Start, and it reads the room.

It works the same way a handheld SPL meter does: it samples the audio signal from your mic, computes the root mean square (RMS) level over a short integration window, and converts that into a dB reading you can actually read. The scale runs from 0 dB (total silence) to 130 dB (think jet engine at close range). Most everyday environments sit somewhere between 40 dB and 85 dB.

A quick note on accuracy: browser microphones are not laboratory instruments. The readings you get here are a close approximation — useful for getting a real sense of how loud your environment is, but not a replacement for a certified SPL meter if you need legally precise measurements. For most practical uses — checking if your home office is too loud, seeing how noisy a restaurant is, or monitoring a baby's room — this works just fine.