Smart Home Apps: Local or Cloud-Based

Local control is more reliable for a smart home: devices can keep working without an internet connection. The cloud is convenient for remote access and manufacturer services, but it depends on your network connection and the availability of an external platform.

The choice isn’t always between one option and the other: some functions can run at home, while others use the cloud. This article explains how smart home apps work in both cases and what matters most to you: independence, remote control, or convenience.

• 0 external internet connections are required for a local automation between devices if it’s saved on the hub and the home network is working
• 2 architecture options to compare: local control and cloud-based control
• 3 local controllers named: Home Assistant, Homey, and OpenHAB
• 1 home hub can store automations for Zigbee devices

How does local control differ from cloud-based control?

Where the command is processed

With local control, a command travels over the home network through a compatible hub, such as Home Assistant, rather than necessarily going through an external server. With cloud-based control, the manufacturer’s server processes it, so app access and some commands depend on the internet. A device’s Wi-Fi connection alone doesn’t prove that commands are processed in the cloud: the app may control it locally after receiving a token from a cloud service during setup.

• Local setup: Home Assistant connects devices on the home network; an internet connection isn’t required to carry out a local command.
• Cloud-based setup: The manufacturer’s server is involved in control, so losing the internet connection may prevent the app from accessing the device and disrupt some commands.
• Wi-Fi device: The app may control it locally even if a token was obtained through the cloud during initial setup.

What’s stored on the hub

Automations for Zigbee devices are often stored in the hub’s memory. For example, the hub may connect a sensor’s activation to an action by another device. If you remove the hub, the devices may remain on the network but lose those automations. Automations that require a smartphone or send data outside the home may also depend on the cloud.

What will keep working at home if the internet goes down?

When the internet goes down, automations between a sensor and a device will keep working if the automation is saved on a local hub, the home network is working, and the devices and hub have power. For example, a Zigbee hub can carry out an action between a connected sensor and device without contacting an external server.

What depends on the internet

• Smartphone notifications: Sending a notification outside the home requires an internet connection, so it may not arrive if the connection is down.
• Sending data outside the home: An automation that needs to send information over the internet won’t be able to complete that part without a connection.
• Controlling devices from the app when you’re away: Access depends on the connection method. Without a preconfigured route from the external network to the home hub, remote commands won’t get through.

In other words, an automation saved on a Zigbee hub and remote control through an app are different functions: the first may work within the available home network, while the second requires a way to connect to it from outside.

How do you choose an app and hub for local automations?

For local automations, choose a controller that’s compatible with your specific sensors and devices, and find out in advance where automation rules are stored. Home Assistant, Homey, and OpenHAB are options for a local controller, but the platform name alone doesn’t guarantee support for the devices you need.

Compatibility matters more than the app’s name.

Check the list of compatible models and how each sensor, thermostat, or device connects. If your home has Zigbee sensors, find out which hub connects them to the app and whether automations are stored in the hub’s memory or in the cloud.

• Home Assistant, Homey, and OpenHAB: Compare support for the specific devices you own, not just the apps’ available features.
• Zigbee sensors: Find a hub that receives their signals and check whether the associated automation will keep working on the home network without the internet.
• Climate-control devices: Check whether you can connect a thermostat or valve to your heating settings, and add an air conditioner to an automation.

For each device, check separately what’s available over the local network: viewing its status, controlling it manually, and running automations. Also find out which functions require a manufacturer account, an internet connection, or cloud integration—for example, remote control from outside the home may require an internet connection.

When is a cloud-based setup more convenient than a local one?

A cloud-based setup is more convenient when you need to control devices through an app outside your home network or connect a voice assistant that requires the manufacturer’s server. For example, while away from home, you can send a command to a device through the manufacturer’s service; a local controller without external access can’t provide that connection on its own.

What to check before choosing

Different functions in a cloud-based system may depend on different components: the internet connection, the manufacturer’s server, the home hub, and the app itself. Check separately what will happen if the internet goes down instead of relying only on whether the device appears in the app.

• Manual control: Find out whether the app can reach the device on the home network when the internet is down. Simply adding a device to the app doesn’t guarantee this: the control method depends on how the system is implemented.
• Schedules and automations: Find out where they run—on the hub or on a server. An automation stored locally may keep working without an external connection, while a cloud-based action may be delayed or unavailable.
• Voice assistant: Check which commands require cloud integration and will stop working if the connection is lost.

If your home internet is unreliable, the cloud can still be useful for remote access, but don’t rely on it as the only way to control your devices. For essential functions, check in advance that the specific devices and automations can work independently.

What limitations and mistakes should you keep in mind?

The main limitations of local control aren’t caused by the internet itself, but by individual app functions, dependence on the hub, and how the voice assistant works. Check each component of the system separately: local automations may keep working even when smartphone notifications and sending data over the internet are unavailable.

What to check before buying

• Notifications and internet services. An automation between Zigbee devices may be stored on the hub and run on the home network, but sending a notification to a smartphone requires an internet connection. Find out which functions will remain available if the external network goes down.
• Local control of Wi-Fi devices. A Wi-Fi connection alone doesn’t mean every command goes through the cloud. For example, during setup, an app may get a token from a cloud service to control a device locally; find out whether that access will remain available if the internet goes down.
• Compatibility and hub status. A hub like Home Assistant connects devices locally, but automations that depend on it may stop if the controller is turned off or doesn’t support a device. Check compatibility with the specific model and determine what will keep working without the hub.
• Voice control. Don’t assume it’s fully local without checking the entire chain: the device, app, or cloud service may process the command. Find out which voice commands are available without the internet.

Which option should you choose for your home?

If it’s important that your home’s automations work without an external internet connection, build your system around local control with a hub; use cloud functions for remote access and a voice assistant. For example, a hub can run automations between Zigbee devices inside the home, while sending a notification to a smartphone requires internet access.

• Local system: Suitable for climate control and automations between Zigbee devices that need to work when the external internet goes down. Check that the automations you need are actually saved on the hub.
• Cloud functions: Use them if you need to control your home remotely or connect it to a voice assistant. Keep in mind that remote access and notifications may become unavailable if the internet connection is lost.
• Hybrid system: Decide in advance which tasks use which setup. For example, keep climate control inside the home local and use the cloud for smartphone notifications.

Test automations before buying

Test both the app and the hub: disconnect the external internet and check a command in the app as well as an automation between devices. Then restore the connection and test remote smartphone notifications separately. This will show which functions depend on the cloud and which keep working inside the home.

Frequently asked questions

Written byEkaterina Melehina

Екатерина освещает новости оборудования и технологий, уделяя внимание как крупным событиям, так и мелким деталям, которые могут изменить рынок. Она верит, что даже небольшие изменения могут иметь большое значение для пользователей и бизнеса.