Mic Test Online — Free Mic Check
Free online mic test with live waveform, dBFS level meter, device picker and headphone loopback. Check your microphone works. No upload, runs in browser.
Protect your hearing. Start at a low volume. Never raise the volume to make a tone audible. Levels are shown in dBFS, relative to full scale — not SPL.
How it works
Web Audio API captures an unadulterated microphone stream completely locally in your browser. Real-time time-domain analysis computes live oscilloscope waveforms, peak, and RMS ballistics with zero cloud transmission.
Testing your microphone before meetings, recordings, streams, or gaming sessions ensures your voice is articulate, well-balanced, and free of harsh distortion.
Live Signal & Waveform Inspection
A proper microphone check requires more than just confirming sound exists. You need to verify three fundamental signal properties:
- Active Signal Presence: Ensure the operating system is routing from your intended external microphone rather than a muffled built-in laptop mic.
- Oscilloscope Waveform Symmetry: Clean voice waveforms exhibit natural acoustic peaks and zero-crossings. Flat-topped or squared-off wave peaks indicate severe preamp or ADC saturation.
- Gain Staging Headroom: Spoken voice peaks should comfortably hover between -18 dBFS and -6 dBFS. This provides sufficient dynamic headroom for laughter or raised voices without pushing into 0 dBFS clipping.
Frequently asked questions
How do I test my microphone with this tool?
Select your input device from the microphone dropdown, click 'Start Test', and speak into your microphone. Watch the live oscilloscope waveform and the dBFS level meter to confirm clean audio capture without digital clipping.
What is the purpose of the 'Hear yourself' monitor toggle?
The loopback monitor routes your microphone directly into your output so you can hear your actual acoustic tone in real-time. Always use headphones when enabling this feature to prevent acoustic feedback squeals between your speakers and microphone.
Why does my microphone show clipping?
Digital clipping occurs when incoming sound exceeds 0 dBFS (the maximum level digital converters can represent), resulting in harsh distortion. If the clipping indicator flashes, lower your input gain in operating system settings or move further back from the microphone capsule.
Is my voice recorded or uploaded anywhere?
No. The Web Audio API processes all audio buffers completely client-side in your browser's local memory. No audio stream is ever recorded to a file, stored on disk, or transmitted over any network.
How can I hear myself on a mic test?
Start the test, choose your input, then enable the monitor toggle to route your voice to your outputs with live waveform and dBFS meters. Always wear headphones when monitoring, since speakers feeding back into the microphone create loud squeals. For a recorded check instead, use the 10-second loopback page.