Search for this fault and you will find plenty of dated advice: update a driver, reinstall Flash, download a repair utility. Flash has not existed since 2020, and a modern video chat uses no specific driver at all: it runs on WebRTC, a standard browser component.
In almost every case the cause is a permission. And there are two layers to check, one of which nearly every guide skips.
Layer 1: the browser permission, for this site
This is the one everyone knows. It is set per site, and a refusal is remembered - which is why a "Block" you clicked reflexively six months ago still gets in your way today.
- Chrome and Edge - click the icon left of the address (padlock or sliders), then set Camera and Microphone to "Allow". Reload the page: the change is not retroactive on an open tab.
- Firefox - same place; a crossed-out camera appears in the address bar when a block is remembered. You have to clear it explicitly, not just re-allow.
- Safari on Mac - Safari menu, Settings, Websites tab, Camera, then set the site to "Allow". Safari is the strictest of the four.
- Safari on iPhone - phone Settings, Safari, Camera and Microphone, then "Ask" or "Allow".
Layer 2: the system permission - the most commonly missed cause
Even when the browser has permission for the site, the operating system can forbid the browser itself from touching the camera. The symptom is misleading: the site asks for nothing, or the request is denied instantly.
- Windows - Settings, Privacy & security, Camera. Two switches matter: general camera access, and above all "Let desktop apps access your camera", which is the one people miss.
- macOS - System Settings, Privacy & Security, Camera, then tick your browser in the list. A browser installed later is not there automatically.
- Android and iOS - permissions of the browser app, not of the site.
Black screen, but permission granted
That is a different problem, and it almost always has the same cause: another application already holds the camera. On Windows and macOS, only one program can use it at a time in most configurations.
The usual suspects: Zoom, Teams, Discord, OBS, Snap Camera, the Camera app, or a conferencing tool left running in the background after a meeting. Close them fully - not just the window, the process - then reload the page.
Two more overlooked leads: the physical shutter stuck over a laptop lens, and the keyboard camera switch (an F key with a crossed-out camera icon) that some laptops toggle by accident.
Decoding the error messages
- "Permission denied" / NotAllowedError - permission refused, layer 1 or 2. The most frequent case by far.
- "Could not start video source" / NotReadableError - the camera exists but is already busy, or the system is blocking it. See the section above.
- "Requested device not found" / NotFoundError - no camera detected. This one may genuinely be hardware: USB cable, or a webcam disabled in device manager.
They can hear me but not see me
The signature of microphone allowed and camera denied. The two are often requested separately, and it is very easy to accept one while refusing the other without noticing. Go back to layer 1.
The reverse case - they see you but cannot hear you - follows exactly the same logic on the microphone side.
And if you simply do not want a camera
Worth saying, because plenty of people wrestle with a setting when their real problem is elsewhere: on some platforms the camera is not required. You can stay in text, or use an avatar that represents you on screen without transmitting your face.
We compare the three options on the video chat without a camera page. And if your fault is the connection rather than the camera, that is the other article: random video chat not connecting.