Last weekend, I cut off my internet access, although I left the router powered on for a local network. The goal was to test how my smart home devices behaved without their cloud connection.
The test revealed clear performance gaps. Some devices continued to operate normally.
This breakdown lists devices that held their ground and those that failed, and explains the factors behind their performance.
Google stopped responding when the Wi-Fi went out
As soon as the connection dropped, I said, “Hey Google, turn on the living room lights.” The speaker did not respond, which was a harsh reminder of how dependent voice assistants like Google Home are on the internet.
Most people assume these devices have some built-in smarts, but the reality is that your voice command goes to a remote server, where Google’s cloud-based AI processes it and sends the appropriate response back.
There is no internet, no processing. All the conveniences, such as voice control, voice-activated automation, and asking questions, have become impossible.
Some of my smart lights worked, others didn’t
Source: Philips Hue
I walked to the light switch to test which devices still responded. The Philips Hue bulbs in the living room worked with the app.
The reason is clear. A dedicated Zigbee hub, the Philips Hue Bridge, manages communication between the bulbs and the smart home.
Zigbee is a wireless mesh protocol independent of the internet. If the phone and Hue Bridge share a local network, the system operates without the cloud.
I turned the lights on and off, dimmed them, and adjusted the scenes from the Hue app without issues.
Next, I tested a side‑table lamp with a Wi‑Fi‑only bulb. I tapped its companion app button, but it failed to respond.
Unlike the Hue system, this Wi‑Fi-only bulb needed its manufacturer’s cloud servers and could not authenticate or send commands.
The smart security system lost live view but kept recording locally
Source: Blink
I started testing home security by checking the hallway camera. The app’s live video feed failed to load. It couldn’t connect to the cloud where cameras stream without the internet.
However, most cameras from reliable brands can store footage locally and upload it when the internet returns.
The doorbell behaved similarly. It stopped notifications, live view, and facial recognition but continued recording in the background.
Not all smart security cameras behave this way. Cloud‑only devices become wall‑mounted decorations without the internet.
Next, I checked my locks. I couldn’t unlock the door with the app or voice control. However, entering the PIN on the keypad unlocked the door.
Most smart locks include emergency overrides to prevent lockouts during outages. It also relocked after 30 seconds.
The smart thermostat worked in person but not remotely
While local control was solid, I lost access to most features that make smart thermostats smart.
- The app on my phone couldn’t connect to the thermostat remotely, so I couldn’t push any new settings or modify schedules from the app.
- Presence sensing only worked partially.
- The motion sensor on the thermostat still detected movement in the hallway, so it could tell when someone was home.
However, it couldn’t receive location updates from my phone’s GPS, which meant geofencing automations stopped working.
Features like auto-away, which use your phone’s location to determine if the house is empty, didn’t trigger. The thermostat couldn’t tell if I had left or returned.
- Brand
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Ecobee
- Integrations
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Alexa, Google, HomeKit, SmartThings
- Connectivity
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Dual-band Wi-Fi
When it comes to Alexa-controlled smart thermostats, they don’t get much better than the Ecobee Premium. It’s not just compatible with Alexa; it has a built-in microphone that ensures you’ll always have a direct line to the voice assistant whenever you’re in range of the thermostat. Its room sensors and radar motion detectors are among the most consistent in the smart thermostat category, and the metal body and glass touchscreen mean it looks great in nearly any home. If we had to pick out something negative, it would be that the app and device don’t respond 100% instantly when you issue a command, but even that’s a minor issue.
The smart TV worked for live TV, but not much else
Image source: Lucas Gouveia / Android Police | Vasyl Shulga / Shutterstock
The TV turned out to be a mixed bag in this no-Wi-Fi experiment. My main screen in the living room is a Google TV, with Google Assistant built right into the system.
It displayed over‑the‑air channels via antenna, but streaming apps like YouTube, Netflix, and Disney+ would not load. Attempts to view downloaded content also failed for most apps.
However, casting still worked. I could cast local content from my phone to the TV over the local network.
Manual controls worked, but smart features on the vacuum didn’t
Source: Ecovacs
Next up on my test bench was the robot vacuum. I have it set to run a scheduled cleaning every morning.
However, with the Wi-Fi unplugged, that scheduled run time came and went with no movement. Still, core functionality remained intact.
When I pressed the power button, the vacuum started cleaning, followed its mapped route, and returned to the dock. While I couldn’t update the map, it remembered the layout from previous mapping sessions.
That said, I lost all remote visibility. I didn’t get any of the usual push notifications.
Offline reliability depends on how your devices process information
Offline performance depends on whether a device processes intelligence locally or in the cloud.
Devices using local mesh protocols, such as Zigbee, Z‑Wave, or Thread, communicate with each other or a local hub without the internet. Wi‑Fi–only devices depend on the cloud.
They send commands to a remote server and await a response. Without the internet, the communication chain breaks.
Many inexpensive bulbs, switches, and cameras lack LAN control and are unusable when offline. Local-first platforms like Home Assistant keep logic and automation local, ensuring that your automations remain active even without an internet connection. Plan for local control that keeps your automations alive, even when the internet is unavailable.
