The built-in tools are a good start but they don't simulate most of network issues and don't do anything about existing websocket connections. On windows I use

The built-in tools are a good start but they don't simulate most of network issues and don't do anything about existing websocket connections. On windows I used clumsy that was much more realistic. On some tablets, I used my microwave oven or my feets to walk away from the Wi-Fi.