Shelly i4 Gen3
No relay output · Triggers scenes · Electrician install
In stock · Ships in 1 to 2 business days
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4-button wall plate that controls other Shelly devices?
The Shelly i4 Gen3 reads 4 momentary buttons and sends actions over Wi-Fi to any Shelly, so a scene plate drives lights in other rooms with no load wiring behind it. Diagram: Shelly.
Dimming up and down from a 4-button plate?
2 of the Shelly i4 Gen3 inputs brighten and dim a Shelly dimmer elsewhere, the other 2 run scenes. The plate carries no load, just the 4 button wires. Diagram: Shelly.
1 switch that controls several Shelly devices at once?
Each Shelly i4 Gen3 input triggers actions on multiple Shelly relays and dimmers, so an all-off button at the front door, or a scene button in the lounge, needs no extra wiring. Diagram: Shelly.
Smart bulbs that the customer still wants on a wall switch?
The Shelly i4 Gen3 turns a plain wall switch into a controller for Shelly smart bulbs, so the switch toggles the bulb over Wi-Fi instead of cutting its power. Diagram: Shelly.
Key features
Reads inputs, not loads: no relay output; it triggers scenes and other devices instead of switching power directly.
4 independent inputs: 1 device multiplies a single wall point into up to 16 trigger actions.
Scene-trigger companion: pairs naturally with wall switch consoles for multi-scene rooms.
No hub required: runs standalone on Wi-Fi with a built-in web interface.
Know the limits: Alexa works via virtual-device routines only; Google Home and SmartThings are not supported.
Works with
Amazon Alexa
via virtual device routine
Home Assistant
Shelly Smart Control app
MQTT
KNX
About this product
The Shelly i4 Gen3 is a dry input reader, not a relay. It doesn't switch power itself. Instead, it watches up to 4 existing switches or buttons and uses those signals to trigger scenes, control other Shelly relays and sensors, or fire off HTTP/MQTT actions elsewhere in the system. 1 press can execute up to 16 different actions across a smart home setup.
It's the natural companion to a multi-button wall plate: wire 4 inputs behind a switch console and each button can run its own scene, or a combination of scenes, without needing its own relay hardware. Because it reads inputs only, it fits neatly into retrofit projects where the switching is already handled by other devices.
Built on Shelly's Gen3 chip with 8 MB of memory, it supports scripting, KNXnet/IP, and the same range of local protocols (MQTT, webhooks, HTTP) as the rest of the Gen3 range, and needs no hub to operate.
Model: S3SN-0024X
Input-only controller wired to existing switches/buttons behind the wall plate: licensed electrician required for the mains-voltage terminals even though it switches nothing itself.
Tech specs
Physical
| Model | S3SN-0024X |
| Dimensions | 37 x 42 x 16 mm |
| Weight | 19 g |
Electrical
| Max load | N/A: input-only device, no relay/load output |
| Power monitoring | No |
| Operating temperature | −20 to 40 °C |
Connectivity
| Wi-Fi | 802.11 b/g/n |
| Bluetooth | 4.2 with BLE |
Compatibility
| Compatibility notes | Input-only: no relay output, doesn't switch loads. Alexa supported via a virtual device routine only; Google Home and Samsung SmartThings explicitly not supported. |
In the box
| What's in the box | 1 × Shelly i4 Gen3, quick start guide |
Warranty
| Manufacturer warranty | 3 Years |
| Free Ohmly extension | +1 Year Free Ohmly Warranty |
