Microphone Test - Check Your Mic Online

How to use this tool

1. Choose a microphone if the device selector is available, then click "Start Mic Test" and allow access.
2. Speak or make a noise. Compare the RMS level and peak reading, and check whether the waveform responds.
3. If there is no response, check the browser-reported settings and your system audio input, then try another microphone if available.
4. Click "Stop" when done.

What does the microphone test show?

The test displays a live RMS level in dBFS, a separate peak reading, and a waveform showing the recent shape of the signal. RMS summarizes average energy across a short audio window; peak is the largest absolute sample in that same window. A brief peak near 0 dBFS can distort even when the average level looks moderate, so the red CLIP light flags peaks within 0.5 dB of full scale.

Understanding dBFS

dBFS (decibels relative to full scale) measures digital audio against its maximum representable level. The conversion is 20 × log₁₀(amplitude); 0 dBFS is full scale, while negative values show how far below it a signal sits. For example, a 0.5 linear peak is about −6 dBFS. Normal speech RMS often falls between −30 and −12 dBFS, though microphone distance, speaking style, and operating-system gain all affect the reading.

Your microphone audio never leaves your device

Audio is analysed with the Web Audio API AnalyserNode in this browser tab. The tool does not record or transmit microphone audio. If you explicitly choose a microphone, only that device preference is saved in this browser so other Toolcroft media tools can reuse it; use Forget beside the selector to clear the saved choice.

The settings panel shows values the browser reports for the active input track, such as sample rate, channel count, echo cancellation, noise suppression, automatic gain, and latency. Some browsers omit these values, and a reported processing setting may describe browser behavior rather than an operating-system setting. A dash means the browser did not provide that detail.

For a pre-call check, speak at your usual distance and volume. A steady RMS reading in the normal range with peaks comfortably below full scale suggests that the input is active and has headroom. This is a relative digital level check, not a calibrated sound-pressure meter; use the Decibel Meter tool for a separate acoustic-level estimate. The waveform and meter can pause while a browser tab is in the background.

Gain staging reference

Professional audio targets a recording level of −18 to −12 dBFS for speech and vocals. This leaves enough headroom (distance from 0 dBFS) to absorb unexpected loud moments without clipping. The standard "−18 dBFS = 0 VU" alignment comes from broadcast standards (EBU R68, SMPTE RP155).

• −60 to −30 dBFS: very quiet - background hiss, whisper
• −30 to −18 dBFS: quiet speech, normal room
• −18 to −12 dBFS: ideal target for voice recording
• −12 to −6 dBFS: loud speech, close mic - acceptable but watch peaks
• −6 to 0 dBFS: approaching clip - reduce gain
• 0 dBFS: clipping - digital distortion, avoid

Microphone types

Troubleshooting common problems

• Permission denied: the browser needs explicit microphone access. Click the lock icon in the address bar and allow microphone, then reload.
• Clipping / distortion: input level is too high. Lower the gain on your audio interface or move the microphone further from the source.
• Background hiss: either the gain is too high (lower it and move the mic closer) or a condenser mic is in a noisy room. Try noise suppression in your OS settings.
• Dropouts / stuttering: often caused by USB bandwidth issues. Use a different USB port or cable, or reduce sample rate in your audio interface settings.