Question 1

Is this decibel meter free?

Accepted Answer

Yes, and every feature stays free: dBA/dBC/dBZ weighting, the calibration offset, the live "as loud as" comparison, the loudness alert, and the full history graph. DecibelPro, the most feature-rich competitor checked for this tool, skews toward enterprise compliance documentation instead, with a "Pro" nav item and OSHA time-weighted-average tracking built for workplace-safety professionals rather than someone who just wants to know how loud their room is right now. Nothing here pushes you toward a track like that.

Question 2

How accurate is an online decibel meter?

Accepted Answer

Treat it as a relative estimate, not a lab measurement. Consumer microphones and browsers aren't calibrated instruments, so the reading is built from your mic's raw signal mapped onto a plausible dB scale, adjustable with the calibration slider if you have a trusted reference meter to match it against. It's accurate enough to tell a quiet room from a loud one and to track how a sound changes over time, which is what most people actually need.

Question 3

Does this decibel meter use my microphone, and is my audio uploaded anywhere?

Accepted Answer

It uses your microphone, yes, because that's the only way to measure sound level, but the audio never leaves your device. Every calculation, from the raw level to the frequency weighting, runs in your browser through the Web Audio API, and this tool doesn't have a server to upload anything to in the first place.

Question 4

Why does my browser say microphone access is blocked?

Accepted Answer

Your browser is blocking this page's microphone access. On mobile, and in Safari or Firefox, there's no microphone icon in the address bar the way there is in desktop Chrome. Look for a site info or Shields icon next to the address bar instead, or check your browser's privacy/site settings. Allow microphone access there, then click "Start microphone" again.

Question 5

What's the difference between dBA, dBC, and dBZ?

Accepted Answer

dBA weights frequencies the way human ears actually perceive loudness, and it's what OSHA's and NIOSH's workplace noise limits are based on, which is why it's the default here. dBC is flatter and only rolls off at the very low and very high end, better suited to loud, bass-heavy sound like machinery or a subwoofer. dBZ applies no weighting at all: the raw signal, unadjusted. Switch between them from the dropdown below the meter.

Question 6

How loud is too loud? When does noise start damaging my hearing?

Accepted Answer

Around 85 dB, sustained over time, is the OSHA/NIOSH action level where hearing damage becomes a real risk, and shorter exposure is allowed the louder it gets from there. This tool watches for exactly that: once your reading holds above 85 dB for a few seconds, a safety note appears rather than needing you to track the number yourself.

Question 7

What does each decibel level sound like in real life?

Accepted Answer

The line under the live reading updates continuously with a real-world comparison, from "about as loud as a whisper" up through a vacuum cleaner, city traffic, and beyond. Four of the five competitors checked for this tool ship a reference chart, but every one of them is a separate, static list you have to scroll to and match against your own number yourself; none tie it to what the microphone is actually hearing the way this does. The full chart is further down the page too, for browsing on its own.

Question 8

How many decibels is a vacuum cleaner, or a jet engine?

Accepted Answer

A vacuum cleaner runs around 70 dB, and a jet engine at takeoff is around 120 dB or louder up close, both roughly per the reference chart below the meter. That chart runs from the threshold of human hearing at 0 dB up to the threshold of pain, so any everyday sound you're curious about is probably on it.

Question 9

Can I get an alert when it gets too loud?

Accepted Answer

Yes. Turn on the alert, set your own dB threshold, and crossing it triggers a steady color change plus an optional short tone, not a flashing or repeating alarm. None of the five web competitors checked for this tool ship anything like it; the closest matches were dedicated hardware and phone apps (Noisez, Sound Level Alert), not a browser tool.

Question 10

Can I calibrate this decibel meter to match a real sound level meter?

Accepted Answer

Yes, with the calibration slider: nudge the reading up or down until it lines up with a trusted reference meter, no extra hardware required. checkhearing.org, one of the five competitors checked for this tool, offers calibration too, but only through a manual workflow that requires an external certified meter or acoustic calibrator — the self-serve slider here covers the same "match my own reference" job without needing to own one.

Question 11

Is this accurate enough for an OSHA complaint or a legal noise dispute?

Accepted Answer

No. A consumer microphone isn't a calibrated measurement instrument, no matter how the reading is processed, so no browser-based tool, including this one, can honestly claim certified or legal-grade accuracy. For an OSHA complaint or a formal noise dispute, you need a calibrated professional sound level meter.

Question 12

Does this work on mobile?

Accepted Answer

Yes. The live meter, every weighting mode, calibration, the history graph, and the alert all work on any modern mobile browser with microphone access, the same as on desktop.

Decibel Meter

Level over time

What different sound levels are like

Frequently asked questions