My smart home devices stopped working after a router change. What is the fastest way to get everything back online? - good or bad

[Finley]

Changed router and now every smart device is offline. About thirty devices across bulbs, plugs, sensors, and a few cameras. They are all on 2.4GHz. The new router has the same SSID and password as the old one.

Why is this not working and what is the order of operations to fix it?

[Ronan_34]

Same SSID and password should work but some devices bind to the MAC address of the router not just the network name. A factory reset on stubborn devices is usually the fix

[Lucy_35]

Check whether your new router is broadcasting on both 2.4GHz and 5GHz under the same SSID. Many smart home devices cannot handle a combined network and will fail to connect even though the name matches

[Brittle Ronan]

The most reliable fix for bulk smart home reconnection is to set the new router's 2.4GHz SSID and password to match the old one exactly and then power cycle every device in the house

[Shane]

What brand are the majority of the devices. Zigbee and Z-Wave devices should not care about the router change. If those are offline your hub is the problem not the router

[WaveFunction34]

The hub if you have one needs to re-pair to the new router before the devices will come back. That is the most common single point of failure in this scenario

[Skibidi]

If they are all cloud dependent devices the cloud service might have the old router's MAC cached. Logging out of the associated app and back in sometimes clears this

[Piston]

Power cycle order matters. Router first, let it fully boot, then hub if you have one, then devices in groups starting with the most central ones

[MJF]

Some Tuya based devices are notorious for refusing to reconnect after router changes without a full factory reset and re-setup. Budget thirty minutes per dozen devices if that is what you have

[Wizard]

The fastest approach if you have a lot of devices is to set up the new router with identical network settings first and see how many come back automatically before troubleshooting individual devices