What this site is for
Decibel Reader helps you observe how the signal reaching your microphone changes. Compare a fan setting, a window position, or the sound at two places in a room. Start in your browser, read the live estimate and energy-based average, then stop and save a local report if you need one.
The site is free to use and does not require an account. There is no audio upload, recording library, or remote measurement service. The microphone signal is processed in the page while you choose to measure.
A useful estimate with an explicit boundary
An ordinary browser microphone does not supply a verified relationship between digital amplitude and sound pressure. Our main display is therefore labeled Estimated dB. The raw digital level, dBFS, is available in Settings. Reference alignment can adjust the display under one condition; it does not make the device a certified instrument.
We do not claim laboratory acoustic validation, professional certification, an accuracy tolerance, or support for A-weighted dBA measurements. The measurement method and accuracy limits explain the calculation and its practical consequences.
Original guides
The blog covers reading browser levels, making repeatable room comparisons, aligning to a reference instrument, and understanding logarithmic averages. Articles identify their sources and separate worked examples from actual measurements. No example numbers are inserted into the live instrument.
Use the right method for the decision
This tool supports informal observation. It does not determine medical risk, establish workplace compliance, settle a legal noise dispute, or replace an appropriate calibrated sound level meter or dosimeter.
Open the decibel reader or read how local processing and website data work.