Every smart home article tells you to “pick an ecosystem” but nobody explains what that actually means for your network. Here is the real breakdown based on running all three protocols in my house for three years.
WiFi Devices
Best for: Cameras, smart displays, streaming devices. Anything that needs high bandwidth.
Worst for: Sensors, buttons, door locks. WiFi drains batteries fast and adds congestion to your network.
Every WiFi device takes a slot on your router. At 40+ devices, most consumer routers start choking. If you must use WiFi devices, put them on a separate VLAN.
Zigbee Devices
Best for: Sensors, light bulbs, smart plugs, buttons. Zigbee devices form a mesh network – the more you add, the stronger the network gets.
Worst for: Anything requiring high bandwidth or long range without repeaters.
I run about 60 Zigbee devices through a single Sonoff coordinator. Battery-powered sensors last 2+ years. The mesh means I have coverage in every corner of my house and garage. Cost per device is usually lower than WiFi equivalents.
Z-Wave Devices
Best for: Locks, thermostats, heavy-duty switches. Z-Wave has better range per hop than Zigbee and uses a dedicated frequency band (908 MHz in the US) so it never interferes with WiFi.
Worst for: Budget builds. Z-Wave devices cost more and the selection is smaller.
I use Z-Wave for my door locks and a few critical sensors. The 800-series chips are solid, and the frequency separation from WiFi means zero interference.
My Recommendation
Use all three. WiFi for cameras and displays, Zigbee for sensors and lights, Z-Wave for locks and critical devices. The key is keeping as much as possible off your WiFi network.