Webcam test

The preview is mirrored by default because that is what every video-calling application shows you of yourself, and an unmirrored preview feels wrong even though it is what other people see. The toggle turns it off if you want to check text held up to the camera, which is the one case where mirroring genuinely confuses.

The stream resolution is worth a look. A camera capable of 1080p will often hand a page 640×480 unless asked otherwise, and calling software makes the same trade to save bandwidth — so a "1080p webcam" that looks soft on calls is usually negotiating down rather than failing. Lighting matters more than resolution in practice: a cheap camera in good front light beats an expensive one backlit by a window every time, because the sensor exposes for the brightest thing in frame and that window turns you into a silhouette.

When you press stop the tracks are released and the camera light goes out. That is the honest test of whether a page has really let go — if the light stays on after stopping, the page is still holding the stream. Reloading or closing the tab always releases it.