Find answers to common questions
Learn what relative dBFS and device-specific estimates mean, how local calibration works, what data services receive, and when certified equipment is required.
Readings & Calibration
What do the readings mean?
Uncalibrated readings are dBFS and are not acoustic sound levels. A comparison with a real meter can create a device-specific dB SPL estimate, but it remains unweighted and uncertified. Use certified equipment for consequential decisions.
What does calibration do?
Use a calibrated physical sound level meter beside this device, measure the same steady sound, then enter the physical meter's value. A phone app is not a traceable reference. The saved offset produces an estimate only.
Do different devices give different readings?
Yes. Consumer microphones and browser or operating-system audio processing vary in sensitivity, frequency response, gain, compression, and clipping behavior.
Can I use this for OSHA compliance?
No. OSHA compliance requires suitable calibrated equipment and a compliant measurement procedure. This browser estimate cannot determine or document compliance.
Using the Tool
Do I need to download or install anything?
No. This runs entirely in your web browser. Just visit the page, allow microphone access, and start measuring. Works on phones, tablets, and computers.
Which browsers work?
Chrome, Firefox, Safari, and Edge all work fine (desktop and mobile). Make sure you're using a recent version and grant microphone permission when asked.
Why isn't it working on my device?
Common issues: (1) Microphone permission denied - check browser settings, (2) Browser too old - update it, (3) HTTPS required - some browsers block microphone on non-secure sites, (4) Microphone in use by another app.
Can I use this offline?
No, you need an internet connection to load the page. Once loaded, the measurement happens locally, but you can't save the page for offline use.
Privacy & Security
Is my audio being recorded?
No. Everything happens in your browser. We analyze sound levels in real-time but don't record, store, or send any audio data anywhere. Your privacy is protected.
What data do you collect?
We do not upload microphone audio or measurement data. Calibration and history stay in browser storage. AdSense may process ordinary page and device data; GA4 and Umami load automatically on every visit. See the Privacy Policy for details.
Can I use this in sensitive environments?
Microphone audio stays in the browser, but the page still makes ordinary network requests for site delivery, automatically loaded analytics, and permitted advertising. Check your organization's device, network, and web-tool rules before use in sensitive areas.
Can I use this at work without privacy concerns?
Microphone audio and readings stay in the browser, but the site sends ordinary page and device data to analytics providers and may send advertising data according to advertising consent. Follow your employer's device, network, and privacy policies.
Technical Questions
What's the measurement range?
Before calibration the scale is -100 to 0 dBFS. After calibration the interface displays a device-specific estimate from 0 to 140 dB SPL, but the usable acoustic range still depends on the microphone and is not certified.
How often does it update?
The reading updates multiple times per second, giving you near real-time feedback. The display smooths out rapid fluctuations for easier reading.
What's the difference between dB, dBA, and dBC?
dB expresses a ratio; dBFS is a digital level relative to full scale, while dBA and dBC are frequency-weighted acoustic measurements. This tool reports dBFS or an unweighted calibrated estimate, not dBA or dBC.
Can this measure very loud sounds safely?
Do not use this tool to decide whether exposure is safe. Occupational limits use calibrated, frequency-weighted measurements and defined procedures. Move away from uncomfortable sound and follow authoritative safety guidance.
Comparisons
How does this compare to a phone app?
Both can depend on a consumer microphone and device audio processing. Neither should be treated as a certified instrument without suitable hardware, traceable calibration, and a documented measurement procedure.
Should I buy a physical decibel meter?
Use this browser tool for learning and observing relative changes. Use a suitable calibrated sound level meter whenever an acoustic value will inform health, workplace, legal, construction, or regulatory decisions.
Can I use this for OSHA compliance?
No. OSHA compliance requires suitable calibrated equipment and a compliant measurement procedure. This browser estimate cannot determine or document compliance.
What about Amazon decibel meters?
Choose equipment by the relevant standard, measurement range, frequency weighting, calibration documentation, and intended use—not marketplace price alone. This site does not endorse a specific product.
Troubleshooting
The reading seems stuck or wrong
Try: (1) refresh the page, (2) test the microphone in another app, (3) check browser permission and the selected input, and (4) reconnect an external microphone. Calibrate only when you have a suitable physical reference meter.
Why does the dBFS reading approach either end of the scale?
A reading near 0 dBFS may indicate digital clipping, while a reading near the lower end may be close to the device's noise floor or processing limit. Neither value identifies an acoustic SPL threshold.
Calibration didn't help
A single offset cannot correct frequency response, automatic gain, compression, clipping, or a changed device setup. Remove the offset if the comparison conditions or equipment are no longer the same.
Can I use this with an external microphone?
Yes. Select it in system audio settings before starting. An external microphone changes the input path but is not automatically calibrated, traceable, or suitable for certified measurements.