Sound Decibel Meter

Sound Decibel Meter is a free online tool that turns your browser into a sound level meter. It uses the Web Audio API to capture microphone input and compute real-time decibel readings (dBA) with minimum, average, maximum, and peak values. The tool includes a color-coded linear gauge, a live waveform chart, and a calibration slider to adjust readings against a reference source. A noise reference chart provides common sound levels from 0 dB (threshold of hearing) to 140 dB (fireworks). All audio processing happens locally—no recordings are uploaded or stored. Ideal for quick ambient noise checks, room volume estimation, appliance noise comparison, music practice monitoring, and educational demonstrations. Works on desktop and mobile browsers without installing any app.