Real Decibel Meter

Free browser-based sound level meter in 8 languages

Web App

Developer Tools

Audio

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Real Decibel Meter is a free, browser-based sound level meter that measures environmental noise in real-time. 🎯 WHAT IT DOES • Real-time decibel measurement (dB, dBA, dBC, dBZ) • A/C/Z frequency weighting (industry-standard filters) • Fast and Slow time constants • Energy-averaged Leq calculation • Min/max/average tracking • Calibration system for device-specific accuracy 🛠️ INCLUDED TOOLS 1. Real-time Decibel Meter - measure sound levels live 2. Tone Generator - pure test tones (20Hz - 20kHz) 3. Speaker Test - check channels, polarity, and sweep for rattles 4. Hearing Age Test - find your highest audible frequency 5. Noise Exposure Calculator - daily dose from NIOSH 3dB rule 6. Frequency Analyzer - live spectrum visualization 7. Background Noise Test - focused quiet environment measurement 8. Microphone Diagnostics - troubleshoot audio issues 🌍 GLOBAL REACH • 8 complete languages: English, German, Japanese, Spanish, French, Italian, Portuguese, Korean • 11 educational guides explaining the science • Multilingual support for worldwide accessibility 🔒 PRIVACY-FIRST • All audio processing happens locally in your browser • No uploads to servers • No account required • No tracking beyond basic analytics • Session data stays in your device's localStorage 💡 USE CASES • Check if neighbors are too loud • Measure home office noise levels • Test studio monitor volume • Assess classroom acoustics • Workplace noise screening • Document noise complaints • Calibrate speaker systems • Teach students about sound measurement ⚡ TECHNICAL HIGHLIGHTS • Built with Web Audio API for real-time DSP • Static site (Astro) - fast and reliable • Works on desktop and mobile browsers • No dependencies on the client side • Implements proper IEC 61672-style weighting 🎓 EDUCATIONAL Unlike other tools, we explain HOW it works: • Detailed methodology page • Scientific accuracy disclaimers • Calibration instructions • Comparison with hardware meters • Safety and exposure guidance 🆓 COMPLETELY FREE No ads, no paywall, no "premium" upsell. We built this to be genuinely useful and accessible to everyone. Perfect for musicians, homeowners, teachers, safety managers, audio engineers, and anyone curious about the sound around them.