check-mic.com is a browser-based instrument for answering one question quickly: is this microphone working, and is it working well?
Most built-in microphone tests answer only the first half. Windows shows a blue bar, macOS shows a row of dots, and neither tells you your peak level, your noise floor, or whether the signal is clipping. Those are the numbers that decide whether people can understand you.
How it works
The page uses two standard browser features: getUserMedia, which opens the microphone after you grant permission, and the Web Audio API, which analyses the stream. Level, waveform and spectrum are computed from the raw audio inside the tab, several dozen times a second.
The headphone tones are generated live by an oscillator node rather than streamed from a file, so every tone is a clean sine wave at a known frequency. The latency test plays a short click, times its return through the microphone, and repeats the measurement five times.
What we do not do
No audio is uploaded. No recording is stored on a server. There is no account, no sign-in, and no tracking of what you record. When you close the tab, everything the page held is discarded by the browser.
Contact
Corrections, bug reports and feature requests are welcome at contact@check-mic.com.