What still works in a smart home when the internet goes down?

When the fibre drops, some smart homes quietly carry on and others turn into homes where the lights only answer to an app that can no longer reach its server. Which one you get depends on a single design choice: where the decisions are made.

Cloud control vs local control

With cloud control, a switch or sensor reports to the manufacturer's server, and the server sends the command back into your home. It works well until your internet or the vendor's service is unavailable.

With local control, a controller inside your home receives the signal and acts on it directly. The internet is only needed for things that genuinely happen outside the house.

What keeps working on a local system

• Wall switches and scene buttons
• Automations such as motion-triggered lights, curtain schedules and "leaving home" routines
• Door, motion, temperature and leak sensors, and the actions they trigger
• Dashboards and wall tablets on your home Wi-Fi

What usually pauses

• Remote access from outside the home
• Voice assistants — most of them process speech in the cloud
• Devices that only work through the manufacturer's cloud account
• Notifications to your phone while you are away

How to check a device before you buy

1. Look for local protocols: Zigbee, Thread, Matter, or a documented local API.
2. Check whether the device needs its own cloud account to be set up or controlled.
3. If you already own it, switch off the router for ten minutes and see what still responds.

Common questions

Will my smart home still work if the internet goes down?

On a local system, yes for wall switches, scene buttons, automations, sensors and local dashboards. Remote access, voice assistants, devices that only work through a manufacturer account, and phone notifications while you are away usually pause.

How can I check a device before I buy it?

Look for local protocols such as Zigbee, Thread, Matter or a documented local API, and check whether the device needs its own cloud account. If you already own it, switch off the router for ten minutes and see what still responds.

Is a power cut the same as an internet outage?

No. For short power interruptions, a small UPS on the controller and network equipment keeps the system running and avoids a cold restart.

Power cuts are a different case

An internet outage and a power cut are not the same thing. For short power interruptions, a small UPS on the controller and network equipment keeps the system running and avoids a cold restart.

Planning a new system? Tell us about your home and we will mark which devices run locally before you buy anything.