A Home Assistant dashboard that still works when the internet doesn’t

A smart home should still be a home when the internet goes down. The lights should switch, the heating should follow its schedule and the dashboard on the wall should still load.

Home Assistant is good at this, because it runs on a small computer in your house. But it only stays local if the devices and the setup around it are local too. Here is what I check.

Every integration in Home Assistant lists an IoT class on its documentation page. It tells you how the integration reaches the device:

• Local push or local polling means it talks to the device on your own network. It keeps working offline.
• Cloud push or cloud polling means it goes through the maker’s servers. When the internet is down, so is the device.

For anything that matters, like lights, locks and heating, I choose devices with local control. Zigbee, Z-Wave, Thread and ESPHome devices are all good choices. Wi-Fi gadgets that need the maker’s app and an account often are not.

When the internet drops, your router still runs the home network. The homeassistant.local name does not work on every device, though, so give Home Assistant a fixed IP address with a DHCP reservation on the router. Then point the wall tablet at that address, for example http://192.168.1.20:8123.

In Home Assistant, open Settings → System → Network and fill in the local network address. Then, in the companion app, tell it which Wi-Fi network is your home. At home, the app now talks to Home Assistant directly instead of going out to the internet and back.

A card that needs the internet, like a weather forecast or a camera that streams through a cloud service, shows an error when the connection is down. That is fine, as long as the important cards don’t depend on it. I put the local things first: lights, heating, doors and energy. Internet-based cards go at the bottom.

Automations run inside Home Assistant itself. A motion light or a heating schedule never needs to ask a server anywhere else.

A small UPS for the router and the Home Assistant machine helps too. A short power cut then doesn’t restart everything at once.

The only way to know is to try. Unplug the internet cable from your router for ten minutes and walk through the house:

1. Switch a few lights from the dashboard and from the wall switches.
2. Trigger an automation, like a motion light.
3. Open the dashboard on the wall tablet and on your phone.

Whatever breaks is your to-do list. Fix it once, and the next outage is just a quiet evening.