Before you buy, run the webcam test and the FPS test on the camera you already have. Often better light fixes the picture for free. If you still want a new webcam, this is what matters.
Resolution: 1080p is the sweet spot
Zoom, Teams and Meet rarely send more than 720p or 1080p, so a 4K webcam mostly helps with recording, streaming or cropping in. A good 1080p camera is enough for meetings. Check any camera with the resolution test.
Sensor and low-light performance
A larger sensor and a wider aperture (a lower f-number, such as f/2.0) gather more light, giving a cleaner picture in a normal room. This matters more than megapixels. Look for reviews that show the camera in dim light.
Frame rate
30 fps is standard and smooth. 60 fps is nice for streaming. Make sure the camera can keep 30 fps at 1080p in normal room light, not only in bright light.
Field of view
About 65–80° suits one person at a desk. Wider (90° or more) shows more of the room and suits small meeting rooms, but shows more background and can distort faces at the edges.
Autofocus, HDR and auto framing
Autofocus keeps you sharp when you lean in. HDR helps when there is a window behind you. Auto framing follows you as you move, which is useful if you stand or pace.
Built-in microphone
Webcam mics are usually fine for casual calls, but a headset or a USB microphone sounds much better. Test any mic with the mic test.
Mounting and privacy
A good clip should hold firmly on a laptop lid and a thick monitor. A tripod thread adds options. A built-in privacy shutter is worth having.
Compare before you keep it
Run your old and new cameras side by side with compare webcams in your own room and light. That tells you more than any spec sheet.