Camera preview, a real level meter, and playback — thirty seconds before the call instead of five minutes into it.
Your stream never leaves this tab. The browser will ask permission — it has to, because a camera test needs the camera. No audio or video is ever sent anywhere; a recording lives in memory until you stop or close the page.
Your browser will show a permission prompt. Nothing runs until you allow it.
Every call starts with the same two minutes: "can you hear me?", "you're on mute", "I think your camera is off". This mic and webcam test settles it beforehand. You get a live camera preview with the resolution and frame rate it is actually negotiating, a real level meter that moves when you speak, a waveform, and a record-and-play-back button — because hearing yourself is the only way to catch that your headset is picking up the laptop's fan.
Worth being precise, because this is exactly the kind of tool where a privacy claim should be checkable. Your browser will show a permission prompt: a camera test cannot happen without opening the camera. What happens next is the part that matters — the stream is handed straight to the video element and the audio analyser inside this page. No server sees it, and no account is needed. If you press record, the clip is held in memory only (a blob: URL) for playback and is thrown away when you stop or close the tab.
And to be exact rather than merely reassuring: this page is not silent on the network. Like the rest of the site it loads a web font and sends an anonymous analytics pageview, so DevTools → Network is not empty. What you will not find there is a single byte of audio or video — no request carries your stream, because there is no code here that could send it.
In order of likelihood: the wrong input is selected (the dropdown lists everything your system exposes — laptops usually default to the built-in mic even with a headset plugged in); the device is muted in the OS or by the hardware switch on the headset cable; another app has it open — most cameras allow only one program at a time, so a call left running in another tab will block this one; or permission was denied, which the tool detects and tells you. If the camera shows black, check for a privacy shutter before anything else. It is nearly always the shutter.
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