About Noise Meter

Noise Meter started with a simple itch: checking how loud a room is shouldn't require installing an app, creating an account, or wondering where your microphone data ends up. A modern browser already has everything needed to measure sound — so we built the meter as a web page, and kept building from there.

What this site is

noisemeter.co is a small collection of free, browser-based sound tools:

• The Noise Meter — a live, A-weighted decibel readout for whatever's around you right now.
• The Overnight Noise Monitor — leaves the meter running while you sleep and hands you a full night's chart in the morning, spikes and all.
• The Noise Comparison Tool — records short samples in two places and tells you the difference in average and peak dB.
• The Sound Spectrum Analyzer — shows which frequencies make up a sound, which is how you catch a low hum an ordinary meter underrates.
• The Online Tone Generator — plays sine, square, triangle and sawtooth tones at any frequency, for testing speakers, rooms and ears.

Alongside the tools, the blog covers the questions people actually bring to a noise meter: how loud is too loud, what dBA means, how noise affects sleep, how to document a noisy neighbour without losing your mind.

How the tools work — and where your audio goes

Every tool on this site runs entirely in your browser, using the Web Audio capabilities built into Chrome, Safari, Firefox and Edge. When you allow microphone access, the audio is analysed on your device in real time and immediately discarded. Nothing is recorded, nothing is uploaded, and we couldn't listen in even if we wanted to — there's no server on the other end receiving audio. Close the tab and it's as if nothing happened. The full details live in our privacy policy.

An honest word about accuracy

Browser meters read through your device's microphone, which was tuned for phone calls rather than acoustics, and every phone model differs a little. That makes readings here indicative: excellent for comparisons ("which room is quieter?"), trends ("what happens at 3 am?") and ballparks ("is this roughly 70 or roughly 90?"), but not a substitute for a calibrated sound level meter where formal numbers matter — workplace compliance, legal disputes, regulation. We'd rather tell you that plainly on every page than pretend otherwise, and you'll find that disclaimer wherever readings appear.

Who's behind it

This is an independent project, built and maintained by a solo developer with a stubborn preference for small, fast, single-purpose web tools — the kind that load in a second, do one job well, and don't ask anything of you. There's no company, no sales team, and no growth department; the site is supported by unobtrusive advertising, which keeps the tools free for everyone.

Questions, bug reports and ideas genuinely shape what gets built next — several of the tools above exist because someone emailed to ask for them. If you've spotted something odd or want a feature, the contact page has everything you need; most messages get a reply within a couple of business days.