Frequently Asked Questions

It depends on what you compare. Repeatability on a single device — comparing your own readings over time — is good to roughly ±1–2 dB, because device error is largely a fixed offset that cancels out. Absolute accuracy varies by hardware: recent iPhones and iPads typically land within a few dB of a calibrated meter, while Android phones and laptops vary more widely. That makes the meter well suited to workplace screening, classroom management, and environmental monitoring, though it is not a calibrated instrument. For best results, check it once against a reference measurement — the accuracy page gives the ranges by situation, with sources.

No, DecibelPro is a completely online decibel meter that works directly in your web browser. There's no software to download, no apps to install, and no registration required. Simply open the website, grant microphone access when prompted, and start measuring sound levels immediately. This makes it perfect for quick measurements, classroom use, or any situation where you need an instant decibel reading.

dBA (A-weighting) filters sound to match human hearing sensitivity, reducing the influence of low and very high frequencies. This is the standard for occupational noise exposure and OSHA compliance. dBC (C-weighting) has a flatter frequency response and is used for measuring peak noise levels. Our online decibel meter uses A-weighting (dBA) by default, which is appropriate for most workplace safety and environmental noise measurements.

Our online decibel meter provides OSHA-compliant A-weighted measurements and includes features like TWA (Time-Weighted Average) calculations, dose percentage monitoring, and alerts for action levels (85 dBA) and PEL (90 dBA). While it's an excellent tool for preliminary assessments and ongoing monitoring, OSHA may require certified Type 1 or Type 2 sound level meters for official documentation. Always check your specific regulatory requirements.

There is currently no in-app calibration control: the meter uses the same fixed reference offset on every device. You can still correct for your own hardware by hand. Measure a steady source with both this meter and a calibrated reference instrument at the same position, note the difference, and apply it as an offset to your readings on that device. A single-point offset removes most of the absolute error for that device in that browser, though it does not correct frequency response. See the accuracy page for what to expect before calibrating.

Yes! Our online decibel meter is fully responsive and works on smartphones, tablets, laptops, and desktop computers. It functions in any modern web browser including Chrome, Firefox, Safari, and Edge. Mobile devices work particularly well because they have built-in microphones optimized for voice and sound capture. This makes our tool perfect for on-the-go measurements or classroom use with tablets.

Our online decibel meter can measure sound levels from 0 dB (threshold of hearing) to 120 dB (very loud, potential hearing damage). The practical range depends on your microphone's capabilities - most device microphones work best between 30-110 dB. The tool uses a 44.1 kHz sampling rate and covers the full audible frequency spectrum (20 Hz - 20 kHz).

The meter is free with no account and no hidden fees. Real-time measurement, A-weighted readings, peak/average/min/max statistics, OSHA time-weighted average and dose monitoring, the waveform and frequency spectrum displays, and CSV export all cost nothing. There is an optional paid Pro tier for people who need to document readings repeatedly: it adds timed measurement sessions with saved charts and PDF report generation. Everything else stays free.

While our online decibel meter provides accurate measurements, for legal purposes or formal noise complaints, you may need readings from a certified, calibrated sound level meter. Our tool is excellent for documenting patterns, gathering preliminary data, and understanding the scope of a noise issue. Always check with local authorities about their specific requirements for noise measurement evidence.

Our online decibel meter offers several advantages over apps: no installation required, works on any device with a browser, always up-to-date without manual updates, and no storage space needed. It provides the same professional features as top decibel meter apps including A-weighting, OSHA monitoring, and real-time visualizations. The browser-based approach also means better cross-platform compatibility.