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Online decibel meter

Measure the noise around you using your device microphone. Nothing is recorded or uploaded — all processing happens locally in your browser.

Press start and allow microphone access

03570105140 dB

Peak

Average

Calibration offset (dB)

Accuracy. Browser microphones are uncalibrated and apply automatic gain control, so treat this as an indicator, not an instrument. Typical accuracy is within 3–6 dB in the 50–90 dB range. Below ~35 dB the noise floor dominates; above ~100 dB most handset mics clip. Use the calibration offset to align with a known reference.

How to get a usable reading

Hold the device at arm's length and point the microphone at the source, not your body. Remove any case covering the mic port. Take the average over 30 seconds rather than the peak — noise limits are based on time-averaged levels, and a single door slam inflates the peak by 20 dB without meaningfully changing your exposure.

For anything with legal or occupational consequences — a noise complaint, a workplace assessment, a planning objection — you need a calibrated Class 1 or Class 2 meter. Phone measurements are routinely rejected as evidence.

Sound level meters

When a phone app isn’t enough, a dedicated Class 2 meter gives repeatable readings for workplace checks, noisy neighbours or hobby audio.

Class 2 digital SPL meterCalibrated, A/C weighting, data holdLink coming soon

Pocket dosimeterLogs cumulative daily exposureLink coming soon

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What your reading means

Reading	Interpretation
0–30 dB	Very quiet. A bedroom at night or a well-insulated room.
30–50 dB	Quiet. Good for sleeping, reading and concentration.
50–65 dB	Moderate. Normal domestic or office activity.
65–80 dB	Loud but safe. Conversation becomes effortful.
80–85 dB	Approaching the action level. Monitor duration.
85–100 dB	Protection recommended. Exposure time matters.
100–140 dB	Dangerous. Minutes or seconds of safe exposure.

Frequently asked questions

Is an online decibel meter accurate?

It is usually within 3–6 dB between 50 and 90 dB — enough for orientation but not legal or occupational use. Phone microphones are uncalibrated and apply automatic gain control.

Does this record my audio?

No. Audio is analysed in your browser with the Web Audio API and never leaves your device. Nothing is stored or transmitted.

Why won't my reading go below 30 dB?

Below about 35 dB the microphone's own electrical noise floor dominates, so the meter cannot resolve genuinely quiet rooms.

Do I need to allow microphone access?

Yes — the meter analyses live input from your microphone. Access is requested only when you press start and is used solely for the on-page display.

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Sources & accuracy. Reference levels are drawn from published data by NIOSH, OSHA, the CDC, the WHO Environmental Noise Guidelines and the American Speech-Language-Hearing Association (ASHA). Real-world readings vary with distance, room acoustics and the specific source, so treat every figure as a typical value rather than an exact constant. Last reviewed 2026-08-11.