Shelly Plus 1 UL Smart Relay Switch - Compact WiFi & Bluetooth Control

In this review the Shelly Plus 1 UL is presented as a compact, retrofit smart relay for DIYers and homeowners who want to add intelligence to existing wiring without replacing appliances. The bottom line: it is for people who need a small, UL certified relay that fits behind switches and sockets and provides reliable WiFi and Bluetooth control plus cloud and local options. The biggest reason to buy is its combination of a 15A single channel relay in a tiny form factor with support for remote access and secure protocols.

Key Features

• UL certified relay: The Shelly Plus 1 UL offers a certified single-channel relay rated up to 15A so it can safely switch many household circuits and appliances.
• Dual connectivity: Built-in WiFi and Bluetooth let the device work locally or be controlled remotely via the Shelly app without a separate hub.
• Compact retrofit design: Small enough to fit behind wall switches and sockets so existing fixtures can be upgraded without rewiring or major renovations.
• Repeater capability: The unit can act as a WiFi repeater to improve connectivity for other devices in tight installations.
• Secure communications: Support for MQTT, WSS and TLS plus custom certificates provides options for secure local or cloud automation setups.
• App and voice integration: Works with the Shelly mobile app and integrates with voice assistants for hands-free control.

Who It's For

The Shelly Plus 1 UL suits homeowners, renters and installers who want to make lights, garage doors, irrigation systems, heaters or legacy appliances smart without buying new devices. It is ideal for people comfortable working in electrical boxes or who can hire a qualified electrician to install a compact relay behind a switch.

It may not be the best choice for someone who needs a multi-channel controller in a single module or a plug-in module that does not require wiring; users seeking a plug-and-play, non-wired solution should consider different product formats.

Pros & Cons

Pros

• Small form factor that fits behind wall switches and outlets for clean installations.
• Robust connectivity with both WiFi and Bluetooth plus repeater function for flexible setups.
• Wide appliance compatibility thanks to a potential-free contact and 15A rating.
• Security-minded features such as MQTT, WSS and TLS for local and cloud automation.

Cons

• Requires wiring and basic electrical knowledge or professional installation, so not truly plug-and-play.
• Single channel only, so multiple relays are needed for multi-circuit control.

Specifications

Brand	Shelly
Certification	UL certified
Channels	1 channel
Maximum load	Up to 15A
Connectivity	WiFi and Bluetooth (can act as WiFi repeater)
Control	iOS/Android app, cloud and local access, voice assistant compatibility
Warranty	2 years device warranty

Our Verdict

The Shelly Plus 1 UL is a practical, cost-effective option for anyone wanting to retrofit intelligence into existing electrical fixtures. Its compact size, secure connectivity and 15A relay rating make it good value for homeowners and installers who need a hidden, hard-wired control point rather than a plug-in smart device.

Frequently Asked Questions

Can this switch be used with voice assistants?
The Shelly Plus 1 UL supports integration with major voice assistants through the Shelly cloud and local control options.

Does it need a hub to work?
No hub is required; the device operates over local WiFi or Bluetooth and can be controlled with the Shelly mobile app or cloud services.

Is installation difficult?
Installation is straightforward for someone comfortable with in-wall wiring and the device fits in standard electrical boxes, but hiring a licensed electrician is recommended if unsure.