Microphone test
Check whether your microphone works: after one click the page shows a live waveform, volume bar, peak level and dBFS reading, with input device switching. Audio is analysed locally and stays silent by default.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Microphone test
Press start and the browser will ask for microphone permission. Once granted you get a live waveform, volume bar and dBFS reading. Everything is analysed locally and nothing is played back by default.
Result
No test running yet. Press start and allow permission to see the waveform and levels here.
Audio is only used in memory for RMS and waveform maths — nothing is recorded, uploaded or written to disk. The analyser is not connected to the output, so you will not hear yourself.
What this tool does
- Check a microphone before a call: if the waveform moves, audio is actually reaching the browser.
- Debug "they cannot hear me" problems by separating a missing device from a busy device or a denied permission.
- Inspect noise floor and gain: in a quiet room the level should sit below -60 dBFS, and a permanently high reading points at a noisy room or too much gain.
- Compare real-world levels between the built-in microphone, a headset mic and a USB microphone.
Example
Input
Start the test, allow permission and speak at a normal volume (RMS about 0.1)
Output
Level 66.7%, -20 dBFS, band Loud, peak around 0.42, clipped samples 0
The bar maps -60 dBFS to 0 dBFS onto 0–100%, so an RMS of 0.1 gives 20·log10(0.1) = -20 dBFS and (−20+60)/60×100 = 66.7%.
Frequently asked questions
Will I hear myself while testing?
No. The stream is routed into an AnalyserNode for measurement only and never connected to the audio output, so there is no feedback loop. Use your operating system monitoring or a recorder if you want to listen.
The level stays at zero — what now?
Check that the address bar permission says allow rather than block, that the system input device is not muted and its volume is up, and that no meeting app has taken exclusive control. If all three are fine, try another input device.
What is dBFS and what counts as normal?
dBFS is decibels relative to full scale: 0 dBFS is the digital ceiling, so healthy readings are negative. A quiet room sits around -70 to -50 dBFS, speech usually lands between -30 and -10 dBFS, and a reading pinned at 0 dBFS means clipping.
Does it need a network connection or upload my audio?
Neither. Samples stay in memory for RMS, peak and waveform maths, the page makes no requests, and the tracks are stopped the moment you press stop.
Keywords：microphone testmic testaudio inputwaveformdBFS麦克风测试录音检测音量检测波形设备检测