This online decibel meter listens through your microphone and shows a live level with min, average and max. A browser cannot read a calibrated sound pressure level, so the number is an estimate. Set the calibration offset once against a real sound level meter, and treat the result as a rough guide. Audio is analysed in the page and never recorded or sent.
| Shows | Live level, minimum, average and maximum |
|---|---|
| Accuracy | Uncalibrated; set the offset against a real meter |
| Privacy | Audio is analysed in your browser, never recorded or sent |
| Cost | Free, no sign-up |
By Ship AI Lab. Last updated .
Why a browser decibel meter is only an estimate
A decibel meter needs a microphone with a known sensitivity. Phone and laptop microphones differ, and a web page cannot see how sensitive yours is. What the page can read is the strength of the signal compared with the loudest signal the microphone can pass, which is a level in dBFS. Adding an offset turns that into a number that looks like a sound level.
That is why the offset is a slider. If you have a real sound level meter, play steady noise, compare the two readings and move the offset until they match. It will then be reasonable for sounds of a similar kind, though a phone microphone still has limits at very loud or very quiet levels.
What the numbers mean for hearing
The US National Institute for Occupational Safety and Health recommends keeping noise at work to 85 A-weighted decibels or less over eight hours, and for every 3 decibels above that the safe time is halved [NIOSH, Noise-Induced Hearing Loss, cdc.gov/niosh/noise/about/noise.html]. NIOSH also says noise is likely harmful if you have to raise your voice to be heard by someone an arm’s length away.
This page does not apply A-weighting, which is a filter that matches how the ear responds to different pitches, so its reading is not directly comparable with an 85 dBA limit. Use the arm’s-length voice test as the practical check, and use a proper meter if you need a real exposure figure.
How to use the online decibel meter
- Start the microphonePress the button and allow microphone access when your browser asks.
- Calibrate if you canCompare with a real sound level meter and move the offset slider until the readings match.
- Read the numbersWatch the live level, and use min, average and max to see how a space changes over a minute or two.
What this meter cannot do
- It is not a certified sound level meter. Do not use it for legal, workplace or safety decisions.
- It has no A-weighting, so it will not match a regulation limit expressed in dBA.
- Some browsers apply automatic gain or noise suppression to microphones. The page turns those off where the browser allows, but not every device obeys.
- A phone microphone is poor at very loud sound, and the reading can flatten out.
Online Decibel Meter questions, answered
How do I measure decibels online?
Press Start microphone and allow access. The page shows a live level with min, average and max. Because it is uncalibrated, compare it with a real meter and set the offset slider.
Is an online decibel meter accurate?
Not on its own. A browser cannot read a calibrated sound pressure level, so the figure is an estimate until you set the offset against a real meter, and it is not A-weighted.
Does the page record my audio?
No. Audio is analysed in your browser to get a level and is never stored or sent anywhere.
How loud is too loud?
NIOSH recommends 85 dBA or less over eight hours at work, with the safe time halving for every 3 dB above that. A practical sign is needing to raise your voice to be heard at arm’s length.
Why is the microphone blocked?
Your browser asks for permission on first use. If you refused, allow microphone access for this site in the browser’s site settings and press Start again.