Volume Level Meter Sound Level & Decibel Meter Online Free - Measure any sound in real time, right in your browser

Yes, 100% free with no hidden fees, no subscription, no premium tier and no registration required. Every feature is completely free: the live dB readout updating 60 times per second, the professional VU meter with peak hold, the 40-segment LED strip display, the analogue needle gauge, the live waveform canvas, the real-time frequency spectrum analyzer, the dB history graph showing the last 60 seconds, the eight environment reference cards, the noise event log with timestamps and the alert threshold control. There are no limits on how long you use the meter or how many sessions you run.

No. All sound measurement and analysis happens entirely within your browser using the Web Audio API. Your microphone audio is never uploaded to any server, never stored in any database and never shared with any third party under any circumstances. The only data that leaves your browser is the microphone permission request to your operating system. When you close or refresh the browser tab, all measurement data is cleared immediately from memory.

dBFS means decibels relative to full scale. It measures the digital signal level captured by your microphone and sound card on a scale where 0 dBFS is the absolute maximum the digital system can handle without clipping. dB SPL (sound pressure level) measures actual acoustic sound pressure in the air using a calibrated measurement microphone referenced to the threshold of human hearing. This browser-based meter measures dBFS because it works with your computer microphone through the Web Audio API. The Environment Reference cards help contextualise dBFS readings against real-world acoustic levels.

This meter provides relative and comparative measurements that are highly useful for monitoring your recording environment, checking noise levels and comparing different conditions. However it is not a calibrated acoustic measurement instrument. Accuracy depends on your specific microphone sensitivity, input gain settings, sound card quality and driver implementation. For professional acoustic measurement requiring traceable dB SPL accuracy, a dedicated calibrated sound level meter conforming to IEC 61672 Class 1 or Class 2 is required. For home, office and recording environment monitoring, this free tool provides reliable and consistent relative measurements.

Peak hold captures the highest dB level reached during your monitoring session and displays it separately from the current reading. The small vertical marker on the VU bar shows the peak hold position. The Peak Hold Time setting controls how long the indicator stays at the peak level before decaying back (2 seconds, 5 seconds, 10 seconds or instant). Peak hold is useful for identifying transient loud sounds that happen too briefly to read on the main meter, for setting appropriate recording levels and for monitoring maximum levels during a live performance or meeting without watching the meter continuously.

The alert threshold sets the dB level at which a noise event is logged in the Noise Event Log. Every time the sound level crosses above the threshold, the event is timestamped and added to the log. The Noise Events counter in the overview panel counts total events during the session. This is useful for monitoring an environment for loud noise occurrences: for example, setting the threshold at -15 dB will log every time someone raises their voice or a loud sound occurs in the room, building a timestamped record of noise disturbances.

The frequency spectrum shows how the energy of the captured sound is distributed across frequencies from 20Hz to 20kHz using a real-time FFT (Fast Fourier Transform) calculation. Low-frequency bars on the left represent bass frequencies like traffic rumble, HVAC hum and kick drum. Middle bars represent the critical mid-range where voice intelligibility and most musical instruments live. High-frequency bars on the right represent consonants in speech, cymbal frequencies and room air. Red bars indicate peak or near-clipping levels in any frequency band.

The eight environment reference cards show typical dBFS ranges for common acoustic environments: near silence, library, quiet room, normal conversation, office, street traffic, music playback and concert levels. Because this meter measures dBFS rather than absolute dB SPL, the reference cards help you understand what your readings mean in practical terms. If your meter shows -22 dB and the Conversation card shows -25 to -15 dB, you can see that your current environment is about normal conversation level. Click any card to highlight it as your current reference point.

Yes. This free online sound level meter works on any device with a microphone and a modern browser including iPhones, Android phones, iPads and Android tablets. On iOS, use Safari as it provides the best Web Audio API support on Apple devices. On Android, use Chrome or Firefox. Mobile browsers will request microphone permission the first time you use the meter. The responsive layout adapts to smaller screens with the meter components stacking vertically for comfortable use on phones.

Most free online sound meters show only a single dB number or a basic bar. This tool provides: a 96px live dB readout with colour classification; a professional gradient VU meter with adjustable peak hold; a 40-segment LED strip display; an analogue needle gauge with labelled arc; a live waveform canvas; a real-time frequency spectrum analyzer with colour-coded frequency zones; a scrolling dB history graph; eight environment reference cards; a noise event log with timestamps; an alert threshold control; microphone selector; and a complete stats panel showing current, peak, average and minimum dB readings, all completely free with no registration.