Decibel Meter - Free Online | FunToolX
Use Decibel Meter online for free, no download required. FunToolX offers hundreds of fun online tools.
Click start and allow the mic to measure ambient volume (dBFS; negative values are normal).
About this tool
Decibel Meter is a free online tool. Measure ambient decibels in real time via microphone.
After opening the page, authorize the microphone to access it, and the tool will collect environmental sounds in real time and calculate the decibel value. Display the current decibel, maximum decibel, and average decibel. You can choose between A weighting (simulating the human ear frequency response) or C weighting (flat response). Data is displayed in numbers and dashboards, and historical charts are supported.
Decibel calculation is based on the AnalyserNode of the Web Audio API. After obtaining time-domain data of the audio signal, calculating the RMS (root mean square) value, and then converting it to decibel: dB = 20 * log10 (RMS / reference). A weighting is realized through frequency domain filtering to simulate the difference in sensitivity of the human ear to different frequencies.
Suitable for rough measurement of ambient noise level, assessment of office, classroom, home noise situation. Note that the browser decibel meter is not as accurate as a professional sound level meter and can only be used for reference and cannot be used for legal compliance testing.
Online decibel meter tool collects environmental sound through a microphone and displays decibel values in real time, supporting A/C weighting and time averaging.