It depends on your internet speed coming to the house, the router you have, and how strong the signal is to the cameras. If you have an N-Router, probably 1 or 2 at most if currently you have less than 6 devices on the router. If you have an AC1900 Router, you could probably connect up to 10 Cameras. If you have a weak signal to where the cameras are going to be, you are going to have a hard to loading the camera, and when it detects motion, it's going to take longer to notify you, and longer for it to actually start recording. It might record in 720 or lower video quality if it's a slow connection. I would download a speedtest app on your phone. Go by the place where you would want to install the camera, and run a speed test, you should have atleast 10 - 20Mbps download, and a minimum of 2Mbps upload. (Ideally 10Mbps, but the higher than upload, the better).