Winner
Updated September 2026
Data from Amazon and official Shelly site.
2026 verdict
Shelly 1PM Gen4 comes out on top for a single metered circuit, adding Zigbee to Wi-Fi and Matter and needing no neutral wire.
It joins a Zigbee network through a hub and routes for other devices, and documents dry and wet contact modes for trigger jobs. The Shelly 2PM Gen3 is the lower priced way to control two circuits: two channels with an interlock mode built for roller shutters, blinds and garage doors, though it requires a neutral. The overlap is large, with energy monitoring, a 16A rating, overheating, overvoltage, overcurrent and overpower protection, the same 37 x 42 x 16 mm body and support for Alexa, Google Home, Apple Home, SmartThings and Home Assistant on both. Pick the Shelly 1PM Gen4 for one appliance you want to measure and control, and the Shelly 2PM Gen3 for shutters or two lights from one box.
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| Feature | Shelly 1PM Gen4 | Shelly 2PM Gen3 | Winner |
|---|---|---|---|
| Price | $28.99 | $24.99 | Shelly 2PM Gen3 |
| Rating | 4.6 | 4.7 | Shelly 2PM Gen3 |
| Connectivity | Bluetooth, Zigbee | Bluetooth | Shelly 1PM Gen4 |
| Relay Channels | 1 | 2 | Shelly 2PM Gen3 |
| Dry Contact Mode | YES | NO | Shelly 1PM Gen4 |
| Zibgee Router | YES | NO | Shelly 1PM Gen4 |
| Warranty | 3 years | 3 years | Tie |
| Safety | Overheating protection, Overvoltage protection, Overcurrent protection, Overpower protection | Overheating protection, Overvoltage protection, Overcurrent protection, Overpower protection | Tie |
| Integrations | Google Home, Alexa, Apple HomeKit, Samsung SmartThings, Home Assistant, Matter | Google Home, Alexa, Apple HomeKit, Samsung SmartThings, Home Assistant, Matter | Tie |
| Energy Monitoring | YES | YES | Tie |
| Wet Contact Mode | YES | YES | Tie |
What the differences mean
One channel or two
The Shelly 2PM Gen3 controls two circuits, or one motor in interlock mode, which is what shutters and garage doors need. The Shelly 1PM Gen4 controls a single circuit and has no interlock mode.
Zigbee
The Shelly 1PM Gen4 can join a Zigbee network through a hub and acts as a Zigbee router. The Shelly 2PM Gen3 is Wi-Fi and Bluetooth only, with Matter on top.
Neutral wire
The Shelly 1PM Gen4 is listed as installing without a neutral; the Shelly 2PM Gen3 requires one. In older boxes that alone can settle it.
Contact modes
The Shelly 1PM Gen4 documents dry and wet contact modes. The Shelly 2PM Gen3 spec sheet does not document either, so for a dry contact trigger the 1PM is the one with it on record.
Which one to buy if
- you are motorizing roller shutters or blinds
The Shelly 2PM Gen3's interlock mode drives both motor directions from one module, with metering on each channel.
- you want to meter and control a water heater or boiler
The Shelly 1PM Gen4 handles 16A on one circuit and measures it.
- you run a Zigbee network
Only the Shelly 1PM Gen4 joins Zigbee and routes for the mesh.
- your switch box has no neutral
The Shelly 1PM Gen4 is listed as not needing one; the Shelly 2PM Gen3 does.
Winner
- + Connectivity: Bluetooth, Zigbee
- + Dry Contact Mode: YES
- + Zibgee Router: YES
- - Price: $28.99 vs $24.99
- - Rating: 4.6 vs 4.7
- + Price: $24.99
- + Rating: 4.7
- + Relay Channels: 2
- - Connectivity: Bluetooth vs Bluetooth, Zigbee
- - Dry Contact Mode: NO vs YES
What owners say
Owners of both Shelly relays trust the metering and say Home Assistant integration is quick and stable. Shelly 1PM Gen4 owners use it on single appliances, watching how often a water heater runs, power-cycling a furnace or automating a dehumidifier, and value its Zigbee repeater role; they complain about an unconventional, poorly drawn wiring diagram and radio switching by button presses that takes a firm touch. Shelly 2PM Gen3 owners use theirs on roller shutters, blinds and garage doors, praising a Wi-Fi link that holds deep in the wall box and replacing pricier shutter actuators, while a minority report a frustrating first pairing, trouble adding it to Alexa and a body slightly thicker than the previous generation.
Price history compared
Every price change of both, in the same store, so the gap between the two lines is what one costs more than the other.
- Shelly 1PM Gen4
- Shelly 2PM Gen3
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Frequently Asked Questions
Shelly 1PM vs 2PM: is the Shelly 1PM Gen4 or the Shelly 2PM Gen3 better?
The Shelly 1PM Gen4 for a single metered circuit, since it adds Zigbee and needs no neutral. The Shelly 2PM Gen3 is the better and cheaper choice when you need two channels or cover control for shutters and garage doors.
What is the biggest difference between the Shelly 1PM Gen4 and the Shelly 2PM Gen3?
The number of channels. The Shelly 2PM Gen3 has two, with interlock mode for motors; the Shelly 1PM Gen4 has one. Both meter energy, are rated 16A and carry the same four electrical protections.
Is the Shelly 1PM Gen4 a Gen4 version of the Shelly 2PM Gen3?
No. The Shelly 1PM Gen4 is a single-channel metered relay from the Gen4 line, adding Zigbee; the Shelly 2PM Gen3 is a two-channel relay from the Gen3 line. They solve different jobs rather than being two generations of one product.
Do the Shelly 1PM Gen4 and the Shelly 2PM Gen3 work with Apple Home?
Yes, both support Matter and Apple Home, as well as Alexa, Google Home, SmartThings and Home Assistant.
Who should buy the Shelly 1PM Gen4?
Anyone metering and controlling one appliance, Zigbee users, and homes with no neutral at the switch.
Who should buy the Shelly 2PM Gen3?
Anyone automating roller shutters, blinds, garage doors or two lights from one box, with per-channel energy monitoring and Matter.
Full comparison table
Compare all 47 Relays side by side
You are looking at two of them. The full table lines up all Relays in the catalog with the same specs, so you can filter by what you need and sort by price or rating.
- 47 Relays
- 53 specs compared
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