Shelly Plus i4

Quick verdict

Shelly has retired the Plus i4 in Europe and names the Shelly i4 Gen3 as its successor; the US store still stocks the UL version at $19.99. The Plus i4 is a purpose-built input device: four switch inputs that detect button presses and send events to Home Assistant (or any MQTT broker). The inputs on this AC model sit at line voltage, so wire ordinary switches to them and use the separate Plus i4 DC for low-voltage contacts. No relay, no load switching - just input detection with single, double, triple and long press support. Wire it behind existing switches to add scene control without replacing anything. It only makes sense inside a home automation setup, but for that use case it is exactly the right tool.

Standout: Four switch inputs that detect single, double, triple and long presses - turns the switches you already have into scene controllers.

Notes last checked Mar 23, 2026.

Compatibility snapshot

Why it stands out

• turns four existing wall switches or buttons into scene triggers with single, double, triple and long press detection
• no relay output means it won't interfere with existing wiring - purely an input device
• excellent local integration with Home Assistant for building complex multi-action automations per button

Reasons to hesitate

• no relay output - cannot directly switch any load, only sends input events
• requires in-wall wiring for power - not a battery device
• niche use case that only makes sense if you already have a home automation system to receive the inputs

Best for

• Home Assistant users who want to turn existing wall switches into multi-action scene controllers
• anyone building a wired button panel for complex automations without replacing the switches themselves

Avoid if

• you need to actually switch a load - this device has no relay
• you do not run Home Assistant or another automation platform to process the input events

Privacy and local-control notes

Fully local via HTTP REST API or MQTT. No cloud account required. Inputs are processed locally and can trigger actions without internet.

Home Assistant support: supported · integration path: Shelly (official core integration, Local Push).

Buying reality check

Price notes: Very affordable for what it does, but only useful if you have an automation platform to handle the input events.

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