Cloud automations vs local: why I moved to Home Assistant

SmartThings is a capable platform, and for a lot of people it is “good enough.” The case against it isn’t a single failure but a pattern: the things I care about most - speed, reliability, and ownership - all point toward running automations locally instead of in the cloud. Here is the reasoning, and the local-first setup I run with Home Assistant.

SmartThings is fine if you want set-it-and-forget-it with basic needs. If you care about response speed, staying in control during an internet outage, and owning your automation logic outright, Home Assistant on local hardware is the better fit. The upfront time is real; the payoff is a home that responds instantly and does not depend on someone else’s servers.

What pushed me toward local

Three recurring frustrations with cloud-dependent platforms stand out:

Routines that wait on a round trip. Cloud automations send a command to a remote server and back before anything happens in your house. That round trip adds noticeable lag to scenes and motion-triggered lighting. Local automation skips it.

No internet, no control. When a cloud service has an outage, anything that depends on it stops responding - including basics like lights and locks. A home that stops working because a data center is having a bad day is not the kind of “smart” I want.

Subscriptions and shifting terms. Cloud platforms can add fees, change features, or deprecate integrations on their own schedule. You are renting the behavior of your home rather than owning it.

Why local wins

The core difference is simple: local automation runs on hardware in your home, while cloud automation runs on someone else’s server that might be slow, down, or changed without notice.

With Home Assistant, automations execute on your own controller, so lights respond when you flip a switch or a sensor trips - not when a cloud API decides to check in. Home Assistant also connects to almost anything, which means you are not locked into one vendor’s ecosystem. A Philips Hue Bridge, Aqara sensors, and Shelly Plus 1 relays - discontinued now, but the Shelly 1 Gen4 that replaced it behaves the same - can all work together in the same automation instead of fighting for ecosystem loyalty. That is the same argument laid out in the case against cloud-only smart home gear.

The hardware you need

You do not need expensive hardware to run Home Assistant. Here is what actually matters:

The controller. Home Assistant Green is the simplest, lower-cost box and handles a large device count comfortably - the easiest current pick. If you are still deciding, compare the best local-first smart home hubs. If you want a dedicated machine with more headroom, a Raspberry Pi 5 or small mini PC running Home Assistant OS is the way to go now that the Home Assistant Yellow was discontinued (October 2025). If you want local voice control, add the Home Assistant Voice Preview Edition.

A Zigbee coordinator. This matters more than any other single part. The Sonoff Zigbee 3.0 USB Dongle Plus ships with coordinator firmware and works with ZHA out of the box - an inexpensive, widely supported choice. The ConBee III and the Ethernet-connected SMLIGHT SLZB-06 are solid alternatives - the SLZB-06 is handy if you want to place the coordinator away from your server to improve radio coverage. See the best Zigbee coordinators for Home Assistant for the full comparison.

Reliable sensors to start. The Aqara Motion Sensor P2 and Aqara Door and Window Sensor P2 are dependable battery devices, though note both are Matter-over-Thread rather than Zigbee, so they join through a Thread border router instead of the coordinator above. The Aqara Climate Sensor W100 adds temperature and humidity with a small display; it runs either Zigbee 3.0 or Thread, never both at once, and it ships in Thread firmware, so putting it on your Zigbee coordinator takes a one-time protocol switch in the Aqara Home app.

Switches: do not overbuy. For lighting that can’t flake out, the Lutron Caseta Diva Smart Dimmer is the pick. I haven’t run Caseta myself; the pick is based on the spec sheet and what other owners say about it. It is not Matter or Zigbee - Caseta uses Lutron’s own Clear Connect RF through the Caseta Smart Hub (formerly Smart Bridge) - but it has a reputation for reliability, and the bridge integrates locally with Home Assistant. For other rooms, the Shelly Plus 1 and Shelly Plus 2PM are flexible relays that run locally over Wi-Fi with a local API. Buying new, the Shelly 1 Gen4 and Shelly 2PM Gen4 are the current versions of those two parts: Shelly has now discontinued the Shelly Plus 1 and the Shelly Plus 2PM alike, though they stay fine if you already own one.

Back up your hub. If you self-host, keep regular backups, and a small UPS for the controller is cheap insurance. The unglamorous parts are what keep the system dependable.

The tradeoffs

Local-first is not free of downsides:

Setup takes time. SmartThings is easy because someone else handles the hard parts. Home Assistant asks you to read docs, configure integrations, and occasionally debug an automation. Plan for a weekend of learning rather than an hour.

Some devices are cloud-only. A few brands simply do not offer local control. Devices like the Ring Battery Doorbell Plus or an Amazon Echo (4th Gen) can still be used with Home Assistant, but they lean on the cloud to do it. (Ring has since superseded that doorbell with the Battery Doorbell Plus 2K.) Know that going in.

You maintain your own system. When something breaks, you are the one who fixes it. The tradeoff for that work is control: you own the logic, and no vendor can change it out from under you.

Matter is still maturing. The “everything just works together” promise is not fully here. Thread setups can be finicky, and for critical sensors, Zigbee and Z-Wave still tend to be the most reliable choices today.