"Do Shelly devices work without internet?"

"Yes. Shelly devices support full local control through Home Assistant without any internet connection or cloud account. This is one of Shelly's biggest advantages over competitors like Tuya. Automations, scheduling, and manual control all work locally."

"Can Shelly devices fit behind existing wall switches?"

"Most Shelly relay and dimmer modules are designed specifically for behind-switch installation. The Shelly 1, Shelly Dimmer, and Shelly Plus series fit in standard electrical boxes. However, wire clearance and heat dissipation must be considered — a professional installer ensures proper fit."

"Should I choose Shelly Gen2 or Gen3?"

"Gen3 devices offer Bluetooth for initial setup and slightly improved specs, but Gen2 devices are very capable and often more cost-effective. Both use the same local API and integrate identically with Home Assistant. A managed setup can recommend the right generation based on your specific needs."

Popular Integration

Shelly & Home Assistant

Protocols & Standards

Shelly devices are Wi-Fi-based smart home products known for their compact size, local API support, and professional-grade reliability. The Home Assistant Shelly integration communicates directly with devices over your local network — no cloud account required.

Shelly offers switches, dimmers, plugs, sensors, and energy meters that fit behind existing wall switches. The Gen2 and Gen3 devices support both HTTP and WebSocket local APIs, providing instant state updates. For professional installers, Shelly’s combination of local control, compact form factor, and reasonable pricing makes them a go-to choice.

Local control No cloud required

Visit Shelly Home Assistant

HA Documentation

How Shelly Works with Home Assistant

Getting Shelly connected to Home Assistant and running reliably.

1

Hardware setup

Connect the required Shelly hardware (coordinator, dongle, or bridge) to your Home Assistant server. The integration discovers compatible devices automatically.

2

Device pairing

Put Shelly devices into pairing mode and Home Assistant adds them directly — no manufacturer app or cloud account needed.

3

Local-first control

All Shelly communication happens locally between your Home Assistant server and devices. No internet required, no cloud latency, no third-party data collection.

Common Shelly Issues

The problems installers run into with Shelly and Home Assistant — and how a managed setup prevents them.

Gen1 vs Gen2/Gen3 API differences

Shelly Gen1 devices use CoIoT/CoAP for state updates while Gen2/Gen3 use WebSocket. Mixing generations in one installation requires different network configurations and may cause inconsistent behavior.

Firmware auto-update disruptions

Shelly's default auto-update setting can push firmware that temporarily changes API behavior. In rare cases, an update has broken Home Assistant compatibility until a new HA release patches the integration.

Wi-Fi congestion in large deployments

Each Shelly device is a Wi-Fi client. Installations with 30+ Shelly devices can overwhelm consumer routers, causing intermittent disconnections. Enterprise APs with higher client limits are needed.

Power monitoring accuracy drift

Shelly energy meters can show calibration drift over time, especially on lower wattage loads. Without periodic validation, energy dashboards display inaccurate consumption data.

Why installers choose managed Shelly setups

Firmware updates tested before deployment with auto-update disabled on client devices
Wi-Fi network designed for device density with proper AP placement and channel planning
Unified Gen1/Gen2/Gen3 management with consistent monitoring across hardware versions
Energy meter calibration verification against utility readings

Learn How We Manage Shelly