Pick the device type and what it's doing, and Smart Home Triage narrows the problem down to its most likely cause — network, hub, power, or app — before you start swapping hardware or resetting things at random.
Select both fields above to see a result.
If a device feels hot to the touch, smells of burning plastic, or a smart plug/switch is sparking or scorched, unplug or de-energize it at the breaker and stop using it — don't run any of the diagnostics below on it. This tool covers connectivity and automation faults, not electrical or fire safety issues; those go to a licensed electrician.
Categories are grouped by how they usually fail, not by brand — a smart plug and a smart lock share almost none of the same failure modes, even from the same manufacturer.
"Offline in the app" and "works manually but ignores automations" point to different layers of the system (network vs. hub logic), so the more specific symptom you pick, the narrower the result.
Each result lists the single most likely cause first, with a short list of checks under it. Do them top to bottom — later checks assume the earlier ones passed.
Most "offline" smart home devices haven't actually failed — their radio link has degraded below a usable threshold. 2.4GHz Wi-Fi, which the majority of budget smart plugs, bulbs, and sensors use, shares spectrum with microwaves, older cordless phones, baby monitors, and neighboring routers. A device that sits at the edge of your router's range, or behind two or more interior walls, can hold a connection well enough to load a settings page but drop the persistent connection an automation depends on. This is why a device often "works" when you open the app (which re-establishes a fresh connection) but silently fails when an automation tries to reach it in the background.
Devices on Zigbee, Z-Wave, or Thread don't talk to your router at all — they talk to a hub or bridge, which then talks to your network. If that hub loses its connection, reboots, or its mesh network reorganizes (which Zigbee and Z-Wave do periodically as devices join or leave), individual devices can appear offline even though nothing is wrong with the device itself. This is the most common cause of "worked yesterday, gone today" faults, and it's why restarting the hub — not the device — resolves a disproportionate number of tickets.
Battery-powered sensors and locks report "offline" as their battery voltage sags, often well before the percentage shown in the app reaches zero — the radio needs more instantaneous power than the rest of the device, so it's usually the first component to fail. Mains-powered devices behind a switched outlet, or on a circuit with voltage fluctuation, can also brown out just long enough to drop their radio connection and re-pair with a different internal state, which is why a firmware update stuck mid-install is a common root cause of a device that responds to some commands and not others.
A device can be online and healthy on your local network while still failing every automation, if the manufacturer's cloud service — which many automation platforms route through, even for local devices — is degraded. This shows up as "manual control from the app works, automations don't," because manual taps sometimes fall back to a local connection while scheduled automations wait on the cloud round-trip. It's also the layer most likely to be temporarily broken by an app update that changes how the device authenticates.
This near-always points to marginal Wi-Fi or mesh signal rather than a hardware fault — see Network and Wi-Fi interference above. The connection is stable enough to hold most of the time but drops under load or interference, which reads as intermittent rather than fully dead.
Mild warmth under sustained load is normal for many plugs. Hot to the touch, discoloration, a burning smell, or visible scorching is not — unplug it and don't reuse it. See the safety box above the tool.
Restart the hub first if more than one device on it is acting up at once — that pattern almost always means the hub, not the individual devices, lost its own connection.
This is the signature of a cloud-service or account-layer fault rather than a local network problem — see App, account, and cloud-service faults above.
Yes — pick the closest device category and the symptom that matches. The diagnostic logic is based on how the device communicates (Wi-Fi direct, hub-based, battery vs. mains power), not the brand, so it generalizes across most consumer smart home hardware.