Shelly generations: Gen 3 vs Gen 4 vs Pro

Shelly names its products two different ways at once, and the two do not line up. Some devices carry a generation number, some carry a name like Plus or Pro, and people compare them as though every name were a generation.

The order is Gen1, then Plus and Pro together as the second generation, then Gen3, then Gen4. Pro belongs to that second generation, which is the part that catches people out: almost every Pro you can buy today runs an older processor than a Gen4, despite the name.

Gen 3 vs Gen 4 vs Pro at a glance

For a new install, buy Gen4. Buy a Pro when the device lives in a switchboard or needs Ethernet, and Gen3 when the model you want does not exist in Gen4 yet.

There is no product called Gen2

Shelly has never sold anything badged Gen2. The second generation shipped as two ranges, Plus and Pro, and Shelly's knowledge base still lists them that way, beside Gen1, Gen3 and Gen4. Shelly's own comparison article does talk about Gen2, so the term is real, but no box carries it.

So if you own a Plus 1, you own a Gen2 device, even though nothing on the packaging says so.

What changed, generation to generation

Gen 3 added memory, Gen 4 added a radio

Shelly describes Gen3 as an improved processor and increased memory over its predecessor, and the spec bears that out: 4 MB of flash becomes 8 MB. The protocol set does not move. Wi-Fi stays 802.11 b/g/n, Bluetooth stays 4.2, and there is no Zigbee. Gen3 is the first generation that can do Matter at all, but only on some models and only once you turn it on.

Gen4 is the bigger step. It carries a wireless chip that runs Zigbee and Bluetooth, making it the first generation with a Zigbee radio, the first with Wi-Fi 6, and the first with Bluetooth 5. It is also the first where Matter is included and switched on out of the box.

Where Pro fits

Pro means DIN rail mounting and an Ethernet port. That is the reason to buy one: a wired connection in a switchboard, where Wi-Fi behind a metal enclosure is often poor. On Ethernet the connection does not depend on Wi-Fi coverage at all, which is as reliable as a Shelly gets.

What you have not been getting is a newer processor. Nearly every Pro sold today runs the same Gen2 hardware as a Plus: an ESP32 with Wi-Fi 802.11 b/g/n and Bluetooth 4.2, with scripting but no Matter and no Zigbee. There are two exceptions. The Pro 3EM energy meter can do Matter once you enable it, and Shelly has announced its first Gen4-based Pro, the Pro 1PM 40A Gen4, which adds Zigbee and Matter. Everything else in the Pro range is still Gen2 inside, so before you buy a Pro for Matter or Zigbee, check that model's own page rather than assuming it has caught up.

Which one to buy

For a new install, Gen4, unless something rules it out. It is the only generation that does Matter without a model lookup, the only one with a Zigbee radio, and the one Shelly publishes ANZ variants of.

Buy a Pro when the device belongs in a switchboard on DIN rail, or when you want it wired to Ethernet instead of Wi-Fi. Buy Gen3 when the model you need does not exist in Gen4 yet. That settles the generation. Which model does the job is a separate question, and the Shelly picker asks four questions to answer it.

Matter, by generation

So "does Shelly support Matter" has no single answer, and "Gen3 and up" is wrong often enough to matter. If you need Matter and have not bought the hardware yet, Gen4 is the answer that does not depend on a model lookup. Either way you still need a Matter hub and IPv6 enabled on your router. Our Shelly and Matter guide covers the pairing steps.

Can you mix generations?

Yes, and most Shelly homes end up mixed. Every generation from Gen1 to Gen4 runs in the same Shelly app, side by side, so you can add a Gen4 relay next to the Gen3s you already own without replacing anything. Home Assistant is the same, since it adds each device individually.

The one exception is a Gen4 running in Zigbee mode. In that mode it leaves Wi-Fi and has no IP address, so it belongs to your Zigbee hub rather than the Shelly app. A Gen4 is one or the other, never both at once.