Fix "another app is using the camera"
Published
You allowed the camera, the permission list says Allow, and the picture is still black or the page says the camera cannot be started. The most common reason is not a setting at all: another program has already taken the device. This article explains why only one program can usually use a webcam at a time, how to find the program that holds it, and what to do when you cannot find one.
What the message means
A webcam hands pictures to one program at a time on most computers. When a second program asks for the same camera, the operating system either refuses or gives it an empty picture. Browsers report that refusal in different ways. A web page sees an error named NotReadableError. The browser's developer documentation describes it as a case where you granted permission and the device exists, but a hardware, operating-system or page-level error prevents reading it. A video call service then shows its own wording, such as the camera is in use, cannot start video, or just a black square.
Windows has its own name for the same situation. Its help pages list the error code 0xA00F4243 for the camera app and describe it as another app or process using the camera, and they advise shutting down background apps that could be accessing it. The microphone behaves a little differently, because many systems let several programs listen to the same microphone at once, so a microphone that is in use is a rarer cause than a camera that is in use. Some headsets and audio drivers do lock the microphone to one program, which looks the same.
Find the program that holds the device
Think about everything that could have opened the camera, starting with the obvious and ending with the strange.
- Another browser tab or window. A second call page, a test page or a forgotten meeting tab can hold the camera. Browsers usually mark the tab that uses the camera or microphone with an indicator, so look through all your windows, including private ones.
- Another browser. If Chrome has the camera, Firefox cannot get it. Close the other browser completely.
- Meeting and chat programs: video conferencing apps, messaging apps with video calls, and the call features inside school or work tools. They often keep running in the background after you close their window.
- Recording and streaming software, including virtual camera tools. These grab the real camera in order to offer a virtual one to other programs.
- The camera app that comes with the operating system, and photo or face-unlock helpers that run in the background.
- Remote support and screen-sharing tools, and security software that watches the webcam.
- On a computer shared by several accounts, another signed-in user's session may be using the camera.
On Windows, look in the system tray and in Task Manager for programs you do not expect. On a Mac, check the menu bar and the Dock for apps with a small dot under them. Apple documents that the camera turns off when you close or quit all the apps that use it, so quitting the suspect apps one after another is a reliable test: when the green camera light goes out, you found the last holder.
Fixes, in order
- Close the program or tab you found, then reload the call page. For a program that sits in the tray, quit it from its menu rather than only closing the window.
- If you cannot find it, close every browser window, wait a few seconds and reopen only the browser you need.
- Restart the computer. Microsoft's help lists a restart as an early step for a camera that stopped working, because it releases every program that holds the device and reloads the driver.
- Unplug an external webcam and plug it into another port, preferably directly into the computer instead of a hub. This resets the connection and often clears a stuck state.
- On Windows, open Settings, Privacy and security, Camera, and check that Camera access and Let desktop apps access your camera are on. If the settings are fine, run the camera troubleshooter in the Get Help app, which Microsoft recommends for Windows 11.
- On Windows, open Device Manager and find the camera under Cameras, Imaging devices or Sound, video and game controllers. If the problem began after an update, select the Driver tab and choose Roll Back Driver. Otherwise right-click the camera and choose Update driver.
- Check antivirus and firewall settings. Microsoft notes that some antivirus programs or firewalls can block camera access, so look for a webcam protection feature and allow your browser.
- On a Mac, quit the browser completely and open it again, then check System Settings, Privacy and Security, Camera for your browser.
Phones and tablets
On phones the same rule applies: one app at a time controls the camera. A video call that was minimised, a camera app running in the background, or a screen recorder can hold it. Close the other apps from the app switcher, and make sure the browser has permission to use the camera in the phone's own settings as well as in the browser. Phones also limit what a web page can do when the screen is locked or the browser is in the background, so keep the call page in front while testing.
When there is no other app
If you have closed everything and the error remains, suspect one of three things. The first is the driver, which may be stuck or damaged, and an update or rollback is the remedy. The second is a privacy switch, either a hardware shutter or a function key, or an operating-system setting that denies the browser. In that case the device looks present but unreadable. The third is a virtual camera: a leftover virtual device can be selected as the default and wait for software that is not running. Select the real camera from the device menu of the call page, or uninstall the virtual camera tool if you do not need it.
A neutral test helps you decide. Open the free camera and microphone test, press Start camera test, and look at the message. A NotReadableError there confirms that the device is held or blocked at system level. A NotFoundError means the system lists no camera at all, which points to cables, drivers or a hardware switch. A NotAllowedError means the browser permission, not another app, is the problem.
Avoid the problem next time
- Quit meeting programs completely when you are done, instead of only closing their window.
- Do not leave test pages open in forgotten tabs.
- Turn off start-with-computer options for camera tools you rarely use.
- Choose the camera explicitly in call services that offer a device menu, so a virtual camera is not picked by default.
- Keep the operating system and drivers up to date, but note down the driver version before a change so you can roll back.
About ChatLite
If ChatLite cannot start a call because of a busy camera, the same steps apply, and a voice call lets you keep talking while you fix the camera.
References
Official documentation used to check this article. Pages are maintained by their owners and may change.
Reviewed against ChatLite's current behavior on .