Camera Tester

The Camera Tester is a quick way to check, from inside the browser, whether your camera is detected and produces an image. It is handy as a pre-check before a video call or an online class. When you click start, the browser asks for camera permission, and the picture appears in a preview box on the page; if your computer has several cameras, a switch button appears. It is a live preview and nothing more: it cannot take photos or record video, does not show the resolution or frame rate, and cannot adjust brightness, contrast, or focus.

How to use it

1. Click 'Start Camera Test'. Your browser shows a permission prompt; allow camera access.
2. After you allow it, the button changes to 'Stop Test' and a black preview box appears below it. The live picture shows up there.
3. If more than one camera is found, a 'Switch Camera (N available)' button appears, where N is the count. Each click moves to the next camera in the list and wraps back to the first after the last.
4. When you are finished, click 'Stop Test'. The camera is released and its indicator light should go off. It is also released when you leave the page.

A usage scenario

A typical scenario: your laptop has a built-in camera and an external USB camera, and your meeting software keeps picking the wrong one. Use 'Start Camera Test', then 'Switch Camera' to look at each in turn and work out which one produces an image and which device it is. To be upfront: an earlier bug that left the preview black (the video element did not exist before the test started, so the picture was never attached) has been fixed in the code, and the video element now always exists and is simply hidden until the test starts. However, we have not tested it with a real camera on different browsers and devices, so we cannot promise it displays correctly everywhere; if you see a black preview, do not conclude that your camera is broken; confirm with your system's camera app or your meeting software.

Supported input and known limits

• We have not tested the preview with a real camera on different browsers and devices, so we cannot promise it displays correctly everywhere; if it is black, cross-check with your system camera app before assuming the camera is broken.
• No resolution or frame rate is requested, so the browser uses its defaults, and the page does not show what was actually chosen.
• Camera names are not displayed, so while switching you can only tell cameras apart by what they show.
• Browsers require a secure connection (HTTPS or localhost) and your approval before using the camera. If you denied it before, re-allow it in the site settings.
• When access fails you see 'Could not access the camera. Please make sure you've granted the browser camera permission and that your device is properly connected.' It does not separate a denied permission from a missing device or one in use by another program.
• If another application has exclusive use of the camera, the browser may be unable to open it.
• No photo or recording, and no mirror or full-screen options.

FAQ: The preview is black after I allowed access. Is my camera broken?

Not necessarily. First check whether the camera light is on. If it is, the browser has the camera and the black box may be a browser or device compatibility issue (we have not tested on real devices); cross-check with your system camera app or your meeting software's preview. If the light is off, check for a physical privacy shutter and whether your system privacy settings allow the browser to use the camera.

FAQ: It says it could not access the camera. What do I do?

Check in order: whether the browser allows this site to use the camera (the settings icon at the left of the address bar), whether the operating system's privacy settings let the browser use the camera, whether a meeting app or other program is holding the camera, and whether an external camera is plugged in properly. Reload the page and test again.

FAQ: Why is there no switch button?

It only appears once two or more cameras are detected. The browser lists devices only after you have granted permission, so you cannot see the button before the first successful start. If you have two cameras connected and it still does not appear, one may not be recognized by the system.

FAQ: Is my video uploaded anywhere?

No. The picture is previewed locally, and the code has no logic to record, save, or send it. See the section below for details.

Privacy and processing

The camera picture is shown live in your browser only. The code requests the camera through the browser's media interface and hands the stream directly to the video element on the page. It does not record, take screenshots, or save frames, and it makes no network request that sends the picture to a server. When you click 'Stop Test' or leave the page, the code stops every camera track.