Choosing between shelly and sonoff for relays

If you’re building a local-first smart home with Home Assistant, relays are one of the most common pieces of hardware you’ll need. They let you control lights, fans, and other dumb devices that weren’t designed to be smart. Two of the most popular brands are Shelly and Sonoff, and both have their place. But which one should you pick?

The answer depends on what you need: your preferred protocol, whether you want cloud dependency, and how much you want to tinker with firmware.

Protocol Matters More Than Brand

The first thing to decide is whether you want Wi-Fi, Zigbee, or Z-Wave. This matters more than choosing between Shelly and Sonoff as brands.

Shelly offers devices in Wi-Fi (the Plus and Wave lines), Zigbee (the Blu series), and even Z-Wave (Wave Pro). Their Shelly Plus 1 is a solid basic relay, while the Shelly Plus 2PM adds power monitoring. The Shelly Wave 2PM is their Z-Wave option if you need longer range and fewer congestion issues.

Sonoff leans heavily into Zigbee with devices like the SONOFF SNZB-02D temperature sensor and SONOFF ZBMINI-L2 mini switch. They also have the SONOFF Zigbee 3.0 USB Dongle Plus (E) which works as a coordinator for Home Assistant. For Wi-Fi, the SONOFF MINI Extreme R4 (Matter) is worth a look if you want Matter support, though it requires a bridge in some setups.

If you already have a Zigbee coordinator, Sonoff’s Zigbee devices are cheap and work well. If you want to avoid yet another protocol stack, Shelly’s Wi-Fi devices are simpler to set up.

Cloud Dependency: The Real Tradeoff

Here’s where the two brands diverge significantly.

Sonoff devices often ship with eWeLink cloud firmware out of the box. For a true local setup, you’ll need to flash them with Tasmota or ESPHome to break free of the cloud. The SONOFF iHost is their attempt at a local hub, but it’s not as mature as Home Assistant. This isn’t a dealbreaker—flashing Sonoff devices is well-documented—but it adds a step.

Shelly devices ship with local-first firmware by default. They work directly with Home Assistant over HTTP or MQTT without any cloud account. This makes Shelly the easier choice if you want to plug and play.

If you don’t mind flashing firmware and want the cheapest option, Sonoff is fine. If you want to minimize tinkering, Shelly wins here.

Power Monitoring and Use Cases

If you need to track energy usage, Shelly has better options in this price range. The Shelly Plus PM Mini Gen3 is tiny and provides power monitoring. The Shelly Plus Plug S is a smart plug with the same capability.

Sonoff’s SONOFF S31 also has power monitoring, but the selection is narrower.

For controlling ceiling fans, the SONOFF iFan04-L Smart Ceiling Fan Controller is a popular 4-relay controller that works with many fan brands. Shelly doesn’t have a direct equivalent.

For Matter support, the SONOFF MINI Extreme R4 (Matter) is notable, though Matter in Home Assistant is still maturing.

Integration with Home Assistant

Both work well once configured. Shelly uses a native Home Assistant integration that auto-discovers devices. Sonoff Zigbee devices show up through your Zigbee coordinator (like the SONOFF Zigbee 3.0 USB Dongle Plus (E) or Conbee III if you prefer).

Wi-Fi Sonoff devices typically need MQTT or the eWeLink add-on if you stay with stock firmware. With Tasmota, they integrate cleanly via MQTT.

Quick Verdict

Go with Shelly if you want the simplest path to local control, prefer Wi-Fi, and value power monitoring in a small form factor.

Go with Sonoff if you have an existing Zigbee setup, want the cheapest Zigbee sensors and switches, or don’t mind flashing Tasmota to escape the cloud.

For most Home Assistant users starting fresh, Shelly is the more practical choice. If you’re already deep in Zigbee, Sonoff’s ecosystem fits naturally.