Shelly 1PM Gen4 vs Shelly 2PM Gen3

The Shelly 1PM Gen4 edges this comparison, adding Zigbee to its Wi-Fi, Bluetooth and Matter connectivity, confirming dry and wet contacts, working as a Zigbee router and installing without a neutral wire. The Shelly 2PM Gen3 wins on price and on offering two channels with a cover mode.

Yes. Both include energy monitoring: the Shelly 1PM Gen4 meters its single circuit precisely, and the Shelly 2PM Gen3 meters power per channel across its two circuits. Energy monitoring is therefore not the deciding factor between them.

Channels, protocols and wiring. The Shelly 1PM Gen4 is a single-channel relay that adds Zigbee, works as a Zigbee router and needs no neutral, while the Shelly 2PM Gen3 is a two-channel relay that requires a neutral but adds an interlock/cover mode for shutters.

The Shelly 2PM Gen3 has an interlock/cover mode designed for roller shutters, blinds and gates, using its two channels to drive a bi-directional motor. The single-channel Shelly 1PM Gen4 is not built for cover control.

Anyone who wants to control and measure a single circuit with protocol flexibility (Wi-Fi, Bluetooth, Zigbee and Matter), dry and wet contacts, a Zigbee router role and a no-neutral install, for appliances like water heaters, boilers and furnaces.

Buyers who need two circuits or a motorized cover, with per-channel energy monitoring built in. The Shelly 2PM Gen3 requires a neutral wire, so confirm your box before installing.