Wi-Fi for a handful of devices, Zigbee once you pass roughly fifteen. Wi-Fi devices need no hub and are the simplest place to start; Zigbee needs a gateway but stays reliable at a scale where Wi-Fi begins to strain.
Wi-Fi devices
Connect straight to your existing router. Nothing else to buy, and setup is a few minutes per device.
The catch is scale. Every device occupies a slot on your router, and consumer routers — particularly those supplied by ISPs — handle a few dozen clients before performance degrades. Add phones, laptops, televisions and cameras to twenty smart devices and problems appear as intermittent unresponsiveness that is genuinely hard to diagnose.
Wi-Fi devices also draw more power, so battery-operated Wi-Fi sensors have short battery lives compared with their Zigbee equivalents.
Best for mains-powered devices in small numbers: a few switches, plugs, and a camera.
Zigbee devices
Use a separate low-power radio network and connect through a gateway, which is the one device that talks to your router.
Advantages:
- Your router sees one device regardless of how many sensors you add.
- Long battery life — Zigbee sensors commonly run a year or more on a coin cell.
- Mesh networking — every mains-powered Zigbee device relays for the others, so coverage improves as you add devices rather than degrading.
- Local operation — many automations run on the gateway and keep working when the internet drops.
Disadvantage — you must buy a gateway, and the gateway is a single point of failure worth siting centrally.
Choosing by device type
- Battery sensors (door, motion, temperature, leak) — Zigbee, clearly. Battery life alone decides it.
- Switches and relays — either; Zigbee ones strengthen the mesh.
- Cameras — Wi-Fi, always. Video needs bandwidth Zigbee does not have.
- A first purchase or two — Wi-Fi, to avoid buying a gateway before you know you want the system.
A practical path
Start with two or three Wi-Fi devices to learn how you actually use automation. If you find yourself wanting sensors in every room, buy a gateway then and add Zigbee from that point — the mesh builds itself as you go.
Mixing both is normal and works fine: most apps present a mixed system as one set of devices, and you choose per device rather than committing the whole house.
Router placement matters either way
Concrete walls and steel doors attenuate both protocols heavily, which is a real factor in Egyptian construction. A device that works on the bench and fails in the wall box is usually a signal problem, not a faulty device.
Zigbee handles this better as it grows, because each mains device extends the mesh. Wi-Fi does not — it needs a stronger router or a mesh access point.
See gateways and hubs and sensors.
Frequently asked questions
Can I use both in one home?
Yes, and most people do. One app usually manages both.
Do I need a gateway to start?
No. Wi-Fi devices work without one.
Does Zigbee work without internet?
Local automations on the gateway continue; remote access does not.