The best free decibel meter online — measure noise levels instantly from your browser microphone. No installs, no accounts.
Grant microphone access to begin
--dB
Min
--
Avg
--
Max
--
60s history0:00
0 dB65 dB130 dB
Silent
0–40 dB
Whisper, rustling leaves
Moderate
40–70 dB
Conversation, office
Loud
70–90 dB
Traffic, vacuum cleaner
Danger
90+ dB
Construction, concerts
Free Online Decibel Meter — Measure Sound Levels Instantly
Our free online decibel meter lets you measure real-time sound levels directly in your browser — no app download, no sign-up, no cost. Just click Start Measuring, grant microphone access, and watch live dB values appear instantly.
What Is a Decibel Meter?
A decibel meter — also called a sound level meter — measures the intensity of sound in decibels (dB). Our online decibel meter replicates hardware functionality using your device's built-in microphone and the Web Audio API, giving browser-based readings accurate enough for everyday use.
Decibel Meter Chart — Common Sound Levels
Use this decibel meter chart as a reference while measuring your environment:
0–20 dB — Near silence, anechoic chamber
20–40 dB — Whisper, rustling leaves, quiet library
40–60 dB — Normal conversation, quiet office, rainfall
60–70 dB — Busy restaurant, television at normal volume
70–85 dB — Vacuum cleaner, heavy traffic, loud music
85–100 dB — Power tools, motorcycle, hearing damage risk zone
100–120 dB — Concerts, jackhammer, construction site
120–140 dB — Jet engine at close range, threshold of pain
How to Use This Sound Decibel Meter
Click Start Measuring and allow microphone access. Switch between dBA (A-weighted, human hearing) and dBC (C-weighted, low-frequency). The 60-second history graph shows noise spikes over time while Min/Avg/Max stats summarise your session. Hit Stop when done, then optionally Export CSV to save a timestamped log.
Why Choose This Free Decibel Meter?
Unlike apps requiring installation, this tool runs entirely in your browser. All audio processing happens locally — no sound data is ever sent to a server. Privacy-first, instant, works on any device with a microphone: laptop, desktop, tablet, or phone.
Outdoor & Professional Use Cases
As an outdoor decibel meter, this tool is handy for measuring traffic noise, construction noise, or evaluating a venue. For professional requirements such as OSHA compliance checks, pair browser readings with a calibrated hardware meter.
Frequently Asked Questions
Can I measure dB with my phone?
Yes. Any smartphone with a working microphone can measure decibels using this browser tool. Open the page in Chrome, Safari, or Firefox, tap Start Measuring, and grant microphone permission. No app download needed.
Is 70 decibels very loud?
70 dB is noticeably loud but not immediately harmful — roughly equivalent to a busy restaurant or vacuum cleaner. Prolonged exposure above 70 dB can cause fatigue; sustained exposure above 85 dB for 8+ hours begins the hearing damage risk zone.
Is 100 decibels really loud?
Yes — 100 dB is very loud and in the hearing-damage zone. Comparable to a motorcycle or chainsaw. OSHA permits only 2 hours of unprotected exposure at 100 dB. Repeated exposure can cause permanent hearing loss.
How loud is 50 dB at night?
50 dB at night is moderately intrusive. WHO recommends keeping outdoor night-time noise below 40 dB for undisturbed sleep. Many noise ordinances set night-time limits between 45–55 dB because this range begins to interfere with rest.
What is the normal decibel range?
For everyday environments, 40–65 dB is considered normal and comfortable. A quiet bedroom is 30–40 dB, a normal conversation 55–65 dB, and a busy office around 65–70 dB.
What is a decibel meter?
A decibel meter measures the intensity of sound in decibels (dB) using a logarithmic scale. Used by engineers, safety inspectors, musicians, and everyday users to monitor noise levels in homes, workplaces, and outdoor environments.
How to use a decibel meter?
Click Start Measuring and allow microphone access. The gauge displays live dB readings. Switch between dBA and dBC modes, watch the 60-second history graph, and use the Min/Avg/Max stats. Hit Stop when done, then Export CSV to save a log.
Are decibel meter apps accurate?
Browser-based apps are accurate within ±2–3 dB — excellent for trend monitoring and general awareness. For legally compliant occupational safety assessments (OSHA, ISO 61672), a certified hardware sound level meter is required.
How does a decibel meter work?
A decibel meter captures sound via a microphone, converts it to an electrical signal, and calculates the RMS amplitude. This is then converted to dB using a logarithmic formula. This tool uses the Web Audio API, processing everything locally in your browser.
What does a decibel meter measure?
A decibel meter measures sound pressure level (SPL) — the overall loudness of all frequencies combined. Weighted modes like dBA and dBC apply filters to better reflect how humans perceive sound.
Is this decibel meter free to use?
Yes — 100% free, forever. No subscription, no account, no hidden costs. The tool runs entirely in your browser with no installation required.
Does it work on mobile?
Yes. Works on any modern browser including Chrome, Safari, Firefox, and Edge on both desktop and mobile. As long as your device has a microphone and supports the Web Audio API, you're good to go.
Is my audio recorded or stored?
No. All audio analysis happens locally in your browser. No sound data is transmitted to any server, recorded, or stored. Your privacy is fully protected.
What is the difference between dBA and dBC?
dBA (A-weighting) filters frequencies the way human ears perceive them — standard for occupational noise assessments. dBC (C-weighting) applies much less filtering and is better for measuring low-frequency sounds like bass-heavy music or heavy machinery.