Shelly Plus i4

Quick verdict

The Plus i4 is a purpose-built input device: four dry-contact channels that detect button presses and send events to Home Assistant (or any MQTT broker). No relay, no load switching — just clean input detection with single, double, and long press support. Wire it behind existing switches to add smart 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 dry-contact inputs that detect single, double, and long press — turns dumb switches into smart scene controllers.

Last checked: 2026-03-23

Compatibility snapshot

Why it stands out

• turns four dumb wall switches or buttons into smart scene triggers with single, double, 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: native / local.

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.

Compare side by side: see switch comparisons →