Decibel Meter Lab

Decibel Meter Lab is a free browser-based online decibel meter and sound level meter designed for instant, real-time acoustic awareness. Its positioning is a lightweight, privacy-first web tool rather than a certified Class 1 or Class 2 instrument. Target audience includes homeowners checking appliance or traffic noise, remote workers and students assessing call or study environments, audio enthusiasts comparing speakers or subwoofers, and anyone curious about environmental sound patterns. Core features include a live dB estimate, min/avg/max statistics, a 30-second history graph, frequency spectrum via FFT, optional alignment to a trusted reference meter, and a save report as PDF. Content features include a decibel noise level chart, guidance on understanding decibels, NIOSH/OSHA/WHO exposure explanations, accuracy limitations, validation protocol, and practical use cases. User experience is simple: click Start Measuring, grant microphone permission, hold the device consistently, measure 30–60 seconds, and compare averages rather than single peaks. Technical features rely on getUserMedia, Web Audio API AnalyserNode, RMS level estimation, dBFS logarithmic conversion, reference offset, local browser processing, HTTPS, and no account or installation. The site emphasizes privacy: microphone audio is processed locally, not uploaded, and reports contain session summaries, not raw recordings. Overall, it is best for everyday noise awareness, relative before/after comparisons, and learning about sound, while official compliance work requires calibrated hardware.