About Online Decibel Meter - Free Sound Measurement Tool
Making sound measurement accessible to everyone with browser-based technology
This browser tool shows relative microphone input in dBFS and, after comparison with a real sound level meter, a device-specific estimated dB SPL value. It is designed for learning and informal comparisons, not certified measurement.
Why We Built This
We built this tool to make microphone-level experiments accessible in a browser. It is useful for learning and relative comparisons, while professional, health, legal, and workplace uses require a certified sound level meter.
Privacy First
Your audio never leaves your device. We process everything locally in your browser, which means no recordings, no uploads, no tracking of your measurements. You get the readings you need while keeping complete control of your data.
Who This Helps
Students learning about acoustics, teachers demonstrating sound concepts, and anyone comparing how microphone input changes between ordinary environments. It is not evidence for health, legal, or workplace decisions.
How It Works
The Web Audio API analyzes microphone input locally and does not create an audio recording or upload readings. Separately, automatically loaded analytics process ordinary page-use data as described in the Privacy Policy.
Publisher and Corrections
Online Decibel Meter publishes and maintains this site. We review tool behavior, privacy disclosures, and reference content when sources or functionality change, and correct factual or technical errors after verification.
Send support questions or correction requests to [email protected]