Home automation in 2025 has evolved far beyond simple voice commands. The demand is for granular control, energy monitoring, and seamless integration with platforms like Home Assistant, Node-RED, and Alexa. Shelly, a brand under Allterco Robotics, has consistently led this charge with innovative Wi-Fi and Bluetooth relays that fit neatly behind existing switches. With the 2025 lineup featuring enhanced processing power, improved Matter support, and refined power metering, here are the top 10 Shelly relays that define modern smart home automation.
1. Shelly Pro 4PM
The Shelly Pro 4PM remains the flagship for electricians and advanced DIY users. Rated for 16A per channel with professional DIN-rail mounting, it controls four independent circuits while providing real-time energy consumption data down to 0.1W. The 2025 revision now includes native Thread border router support, allowing it to bridge non-Matter devices into a Thread mesh network. Its UL-certified safety features, including over-temperature and over-power protection, make it ideal for automating heavy loads like water heaters, EV chargers, or high-wattage workshop tools. The built-in web interface offers scripting capabilities via Shelly’s Gen3 firmware, enabling complex conditional logic without cloud dependency.
2. Shelly 1 Gen3
The third-generation Shelly 1 is the workhorse of hidden automation. At 16A dry contact relay, it fits inside standard wall boxes or behind light switches. The 2025 version introduces dual-core ESP32 processing, reducing latency to under 60 milliseconds for local MQTT commands. Its standout feature is the refreshed power supply circuit that now supports a wider voltage range (12V-48V DC) and includes a true zero-crossing detection for dimming compatibility. Use it to automate garage doors, irrigation valves, or electronic locks. The isolated input allows for direct connection to dry contact sensors or momentary switches without additional wiring.
3. Shelly Plus RGBW2
For lighting designers and accent automation, the RGBW2 Gen2 brings precise 12-24V LED control with 5A per channel. The 2025 update includes dynamic color temperature tuning from 2700K to 6500K using only RGBW strips—no separate CCT strips required. This relay supports 15 embedded lighting effects like ocean wave, candle flicker, and rainbow transitions, all processed locally on device. With over-the-air firmware updates and a redesigned heat sink for sustained current draw, it’s perfect for kitchen under-cabinet lighting, mood zones, or stairwell accent strips that require synchronized animation across multiple units.
4. Shelly 2PM Gen3
The 2PM is the gold standard for controlling two independent loads with high-precision energy monitoring. The 2025 iteration achieves 1% accuracy on power readings via a new sigma-delta ADC, critical for identifying vampire drain or faulty appliances. It supports 16A per channel with a combined 20A limit, making it suitable for dual-bulb ceiling fixtures, shared outlets, or small split HVAC zones. The rolling power statistics graph now logs 24 hours of data locally, accessible via the WebUI even without internet. Enable the “roller shutter” mode to precisely control shades with end-stop calibration feedback.
5. Shelly Pro 1PM
The DIN-rail mounted Pro 1PM is the dedicated single-load meter for panels. Its 2025 rev includes a bi-directional energy counter, allowing it to measure both consumption and production—essential for solar or battery storage setups. With a rated contact of 20A and a maximum surge of 100A for 200ms, it safely controls heat pumps or induction cooktops. The onboard buzzer provides audible feedback for overload alarms, and the integrated webhooks allow push notifications directly to your phone via notification services, bypassing cloud servers entirely.
6. Shelly EM Gen3
Energy monitoring scales up with the Shelly EM, now supporting two external 50A/100A CT clamps in 2025. This device is unique in that it measures energy without breaking the main line—clamps simply clip around the incoming or outgoing cables. The updated firmware includes real-time reactive power (VAR) measurement, critical for identifying power factor issues in workshop or appliance circuits. Use one clamp on your mains and one on a solar inverter to visualize net energy flow. The relay output (16A) can automatically switch on a smart water heater only when solar production exceeds consumption.
7. Shelly Plus 2PM with Dry Contact
Targeted at industrial and commercial retrofits, this 2025 variant offers two 16A relays with fully isolated dry contact inputs. This means it can be triggered by PLCs, humidity sensors, or emergency stop buttons without sharing a ground. The add-on screw terminals no longer require jumpers—each input is independently configurable as a switch, button, or sensor. Its IP54-rated enclosure (available separately) allows installation in sheds, greenhouses, or server rooms where dust and moisture are concerns. The device now supports up to 5 Wi-Fi SSID fallback profiles for roaming across mesh networks.
8. Shelly Uni Plus
The Uni Plus is the universal input/output bridge. In 2025, it adds support for up to five analog sensors (NTC thermistors, 0-10V, 4-20mA) alongside its digital inputs. With a relay output and an isolated 12V-24V supply output, it can power and read sensors while controlling a cooling fan or humidity extractor. This is the go-to relay for automating steam showers, sauna controls, or hydronic heating systems where precise temperature feedback is required. The scripting engine can translate raw ADC values into percentage thresholds, triggering relays at defined sensor points.
9. Shelly Door/Window 3
Though technically a sensor, the Door/Window 3 includes a hidden relay inside its 2025 module. This ultra-compact unit fits into a door frame mortise, connecting to your existing wired doorbell circuit or magnetic lock. When paired with a magnet, it reports open/close status while its internal relay acts on the door strike. The battery-free operation via a solar cell trickle-charges a supercapacitor, promising 10+ years of maintenance-free use. Use it to lock a door via NFC tag scan or trigger entryway lights when the door opens after sunset—all processed on-device.
10. Shelly Pro 3EM-400
The newest addition to the three-phase energy meter family, the 3EM-400 is designed for homes with three-phase power or sub-panel monitoring. It uses 400A split-core CT clamps, suitable for the main feed of large homes or small commercial suites. The 2025 model includes 4G LTE backup connectivity, ensuring energy data uploads even during ISP outages. With three relay outputs rated at 16A each, you can switch three separate loads based on phase-specific load shedding. The new visual phase diagram in the WebUI shows real-time vector balance, helping electricians optimize load distribution across phases.
Technical Integration Considerations
Across all 2025 Shelly relays, three integration layers stand out. First, the adoption of Matter 1.3 ensures compatibility with Apple Home, Google Home, and Samsung SmartThings without proprietary bridges. Second, the Shelly Cloud API v3 now offers 100ms webhook response times, enabling real-time dashboards. Third, the CoIoT protocol allows up to 50 Shelly devices to communicate locally via UDP, forming a decentralized automation mesh that remains functional even if the router fails.
Firmware and Security Updates
All 2025 relays ship with Shelly OS 2.0, which encrypts local MQTT traffic by default using TLS 1.3. The devices support automatic firmware updates via signed manifests, preventing rollback attacks. For advanced users, the open-source Shelly Development SDK lets you write custom automation scripts in C++ or MicroPython, deployable via the web interface. A new “security lock” toggle disables all cloud connectivity, ensuring the relay operates as a pure local device—critical for medical environments or off-grid homesteads.
Power Supply and Wiring Best Practices
When installing these relays, always verify the minimum load requirement. Most Shelly relays require a 10W load on the switch input to maintain stable detection; installing a bypass resistor (2.2kΩ 1W) ensures compatibility with low-wattage LEDs. For retrofits without a neutral wire, the Shelly L models (available for select relays) use a capacitive dropper to operate, though they limit maximum load to 3A. The 2025 lineup also introduces a unified 24V DC rail accessory for panel-mount installations, reducing wiring complexity.
Thermal Management in Enclosed Spaces
High-density installations, such as placing four relays in a single box, require thermal planning. The 2025 Pro models include a derating table printed on the housing: at 25°C ambient, the 4PM can handle 16A per channel; at 50°C, this drops to 8A per channel. Use the built-in temperature sensor to trigger alerts or automatically reduce load current when thresholds are exceeded. For tight enclosures, the silicone thermal pad accessory improves heat transfer to metal backplates.
Remote Access and Geolocation
Shelly’s 2025 relays integrate with the Shelly Smart Control app to offer geofencing without cloud accounts. Using Bluetooth-based presence detection, your relay can trigger arrival scenes when it detects your phone’s BLE advertisement, even if the phone is offline. This feature draws less than 1μA from the phone, preserving battery while enabling truly local presence sensing for automating lights, thermostats, or security systems upon return.
Field-Configurable Inputs
Every 2025 relay with GPIO pins now supports adaptive input classification. Through the web UI, assign any input as a momentary switch, latching toggle, rotation counter (for knob sensors), or open-drain output. The input debounce time is adjustable from 50μs to 500ms, accommodating everything from fast optocouplers to slow mechanical thermostats. This makes a single Shelly relay adaptable to doorbells, motion detectors, water leak sensors, or even a rainwater collection gauge.
Cost-Efficiency and ROI
While the initial hardware cost ranges from $25 (Shelly 1 Gen3) to $180 (Shelly Pro 3EM-400), the potential energy savings are substantial. A Shelly EM monitoring your refrigerator can alert you to a failing compressor by detecting a 15% increase in runtime. The Pro 4PM’s load-shedding scripts can reduce peak demand charges, saving $50–200 annually in areas with time-of-use tariffs. For rental properties, smart relays with lockout timers prevent HVAC overuse, recouping hardware investment within three heating seasons.