Output
Waveform; spectrum; digital dBFS; local clip
UserBenchmark / All Tools / Microphone Level Meter
Audio
Microphone Level Meter
Measure digital microphone signal level in dBFS; physical dB SPL requires calibration.
Free to useNo downloadNo sign-up
Microphone Level Meter · At a glance
Quick answer: Measure digital microphone signal level in dBFS; physical dB SPL requires calibration. dBFS is relative to digital full scale.
Microphone Level Meter
The test loads when you open it. Device access is requested only after you choose to start.
Detailed guide
How to use this tool
- Start the microphone and observe the digital input level.
- Keep input gain fixed when comparing quiet and louder signals.
Input
Microphone permission and an input device
Browser requirement
HTTPS; getUserMedia; Web Audio
Processing
Runs on your device; no tool-result upload
How it works and what the result means
Signal level is shown in dBFS, where 0 is digital full scale. It is not a calibrated sound pressure reading. The noise floor is the lowest observed level, not a laboratory SNR measurement.
Reading the result
dBFS is relative to digital full scale. It does not equal environmental dB SPL, so the page cannot certify workplace or room sound levels.
Why the meter uses dBFS
A microphone returns digital samples after hardware gain and processing. The same room sound can produce very different samples at different gain settings. dBFS measures signal relative to digital full scale. Reporting physical dB SPL requires a calibrated reference and stable hardware gain; this page does not invent that calibration.
What to check next
Automatic gain and noise processing can change the reading. Use a stable input setup for comparisons.
Use HTTPS or localhost, check the selected operating-system input, and close applications that hold the microphone. Stop releases microphone access; recordings remain in your browser.
Frequently asked questions
Can I use this as a calibrated room sound meter?
No. A physical SPL reading requires calibration and a suitable microphone. The browser meter reports digital signal level only.
How do I start the Microphone Level Meter?
Start the microphone, approve access, and speak at a normal level. Watch the waveform and spectrum. Use Record and Finish recording to listen to a local clip.
Does this tool require a download or an account?
No. Open the interactive tool above in a modern browser. The instructions and explanations are available even with JavaScript disabled; running a test needs JavaScript.
Why can two attempts give different results?
Power settings, background tasks, browser scheduling, operating-system input processing and device settings affect measurements. Compare repeated attempts with identical settings rather than the single highest score.