Online Decibel Meter - Free Sound Level Measurement
Measure sound levels instantly with our free online decibel meter. Works in your browser using your device's microphone.
Measurement History
0 records saved
No measurement records yet
Start a measurement to save data
Click "Start Measurement" to begin checking sound levels with your microphone.
You'll need to allow microphone access when your browser asks.
How to Use
Step-by-step guide to measuring sound levels accurately
Decibel Chart
See how loud common sounds are in decibels
Hearing Protection
Learn about safe noise levels and protecting your ears
What You Can Do
Simple tools for everyday noise monitoring
Live Readings
See sound levels update instantly with a visual waveform and color indicators
Track Your Data
View max, min, and average readings from your measurement sessions
Improve Accuracy
Calibrate against a reference meter if you need more precise measurements
Save Results
Download your measurement data as CSV or JSON files
What is a Decibel Meter?
A decibel meter (also called a sound level meter or noise meter) measures how loud sounds are. Our online version uses your device's microphone to measure noise levels in real-time.
The Science Behind Decibel Measurement
Understanding how sound is measured helps you interpret the readings better.
Sound Pressure Level (SPL)
Sound travels as waves of pressure changes in the air. A decibel meter measures these pressure variations. Since the range of human hearing is vast (from the faintest whisper to a jet engine), we use a logarithmic scale to make the numbers manageable.
The Logarithmic Scale
The decibel (dB) is a logarithmic unit. This means every 10 dB increase represents a ten-fold increase in sound intensity. For example, 80 dB is 10 times more intense than 70 dB, and 100 times more intense than 60 dB. A small increase in decibels means a huge increase in noise energy.
A-Weighting (dBA)
Our ears don't hear all frequencies equally well. We are less sensitive to very low and very high pitches. 'A-Weighting' is a filter used in noise measurement to mimic the human ear's response. This tool uses A-Weighting approximations to provide readings that reflect how loud the sound actually feels to you.
How to Use
Allow Access
Grant microphone permission when your browser asks
Start Measuring
Click the Start button to begin checking sound levels
View Results
Watch the live readings and waveform display
Export Data
Save your measurements if you need them later
Why Use This Tool?
Free & No Install
Works right in your browser - no apps to download
Your Privacy Matters
All processing happens on your device. We don't record or store any audio.
Good Enough for Most Uses
Calibration support helps improve accuracy for everyday measurements
Works Everywhere
Use on your phone, tablet, or computer with any modern browser
Common Questions
How accurate is this online decibel meter?
Do I need to download anything?
Is my audio being recorded?
What browsers work with this?
What's a safe noise level?
Important Note
This tool is for general reference and educational purposes. Results depend on your device's microphone quality and may not be as accurate as professional sound level meters. For critical applications (workplace safety, legal documentation, medical purposes), please use certified equipment.