2026 verdict
It also adds Zigbee through a hub with Zigbee routing, and lists overvoltage, overcurrent and overpower protection next to overheating protection. The
Shelly 1 Gen3 is the lower priced option and does everything else the same way: a 16A rating across resistive, inductive and capacitive loads, dry and wet contact modes, AC power with a neutral or DC power without one, and Wi-Fi, Bluetooth and Matter with Alexa, Google Home, Apple Home, SmartThings and Home Assistant, all in the same 37 x 42 x 16 mm body. Pick the
Shelly 1PM Gen4 for appliances you want to measure or a Zigbee home, and the
Shelly 1 Gen3 when switching is all you need.
What owners say
Owners of both Shelly relays praise local control, no-hub setup and quick Home Assistant integration, and both groups find the wiring the step to prepare for. Shelly 1PM Gen4 owners use the metering to drive automations, watching a water heater, power-cycling a furnace or running a dehumidifier, and like that Zigbee mode turns it into a repeater; they complain about an awful, unconventional wiring diagram and radio switching by button presses. Shelly 1 Gen3 owners focus on flexibility, wiring it into a ceiling box when the switch has no neutral, scripting it on the device or flashing ESPHome, and their complaints are no energy monitoring, a tight fit that sometimes needs a box extender and no push notifications.
