The Shelly Dimmer Gen4 is a single-channel retrofit smart dimmer module for controlling dimmable LED light sources, halogen lamps, incandescent bulbs, and compatible electronic transformers. It can operate both with and without a neutral wire, making it suitable for making existing lighting systems smart without pulling new wires.
The Gen4 platform uses Shelly’s most advanced hardware and communication architecture to date. It supports Wi-Fi 6, Zigbee 3.0, Bluetooth 5 LE, and Matter standards, allowing users to choose freely between different smart home platforms. The module can connect directly to a Wi-Fi network, operate as part of a Zigbee network, or be used as a Matter device.
It supports automatic load calibration, full local automation, JavaScript scripting, MQTT communication, KNXnet/IP integration, power metering when wired with neutral, web-based management, and event logging. It is recommended not only for residential use, but also for professional building automation systems.
About Shelly
Shelly is one of the best-known manufacturers in the European smart home market, especially recognized for Wi-Fi, Zigbee, and Ethernet-based automation devices with strong local control support. Most functions can operate without an internet connection, while open APIs make integration with external systems easy.
Shelly devices widely support Home Assistant, openHAB, Homey, Node-RED, KNX, MQTT, and other open platforms. The Gen4 series also offers native Matter support, further improving compatibility between different smart home ecosystems.
Key Features
- Neutral-free operation: Can be used in traditional two-wire lighting circuits
- Trailing edge dimming: Optimized for modern LED light sources and quieter operation
- Automatic dimming calibration: Detects the connected load characteristics automatically
- Matter compatibility: Easy integration into modern smart home systems
- Wi-Fi 6, Zigbee 3.0, and Bluetooth 5 LE support
- Power metering: Real-time power and energy data when wired with neutral
- Built-in web interface for full browser-based configuration
- JavaScript scripting support for local custom automations
- KNXnet/IP support for professional building automation systems
- Zigbee Router function to extend Zigbee network range
- Bluetooth Gateway function for Shelly BLU device integration
- Wi-Fi Range Extender for other Shelly devices
Smart Home Protocols and Platform Compatibility
- Matter: Native Matter support
- Wi-Fi: IEEE 802.11 b/g/n/ax, 2.4 GHz
- Zigbee 3.0: IEEE 802.15.4 with Zigbee Router functionality
- Bluetooth 5 LE: Pairing, local communication, and Shelly BLU integration
- Shelly Smart Control: Full native app support
- Shelly Cloud: Remote access and cloud control
- Home Assistant: Integration via Shelly, MQTT, or local APIs
- MQTT: Local and server-based automation support
- REST API: Local integration and control
- KNXnet/IP: Professional building automation integration
- Webhooks: Event-based HTTP automation
- Additional supported systems: HomeSeer, ioBroker, openHAB, Domoticz, SYMCAN, nymea, Hubitat, HOOBS, and REST API
- Voice control: Compatible with Google Home, Amazon Alexa, and Yandex Alice
Smart Functions
- Remote ON/OFF control and brightness adjustment
- Real-time status monitoring
- Power metering and performance monitoring when wired with neutral
- Event logging
- 20 schedules
- Sunrise and sunset-based automations
- Automatic ON and OFF timers
- Night Mode with separate brightness level
- Minimum and maximum brightness limits
- Adjustable fade time
- Gamma correction for a more linear perceived brightness curve
- Warm-Up function for LED light sources that are difficult to start
- Double-click brightness presets
- Single-button dimming support
- Two-button dimming support
- JavaScript-based local automations
- Local operation without internet connection
- Webhook-based integrations
- KVS data storage
- Virtual components for complex automations
- Weekly recurring schedules with brightness level, fade time, and switching state
- Advanced second-precision schedules for months or a full year ahead
- Adjustable ON and OFF transitions
- Minimum turn-on brightness level
- Configurable dimming speed when holding a button
- Automatic dimming calibration for optimized dimming range
- Detailed event log for switching and configuration events
Additional Features
- Can be used without a hub
- Built-in web administration interface
- Switchable between Matter and Zigbee operating modes
- Automatic load detection and calibration
- Calibration can be rerun after connecting a new load
- Local and cloud operation supported
- Bluetooth Gateway function for Shelly BLU devices
- Wi-Fi Range Extender function
- Zigbee network repeater function
- Advanced building automation integrations via KNX, MQTT, and REST API
- Especially suitable for Home Assistant-based systems
- Power metering functions are available with full accuracy only when wired with neutral
Electrical Functions and Technical Specifications
- Model: S4DM-0A101WWL
- Power supply: 220–240V AC, 50Hz
- Power consumption: < 1.5W
- Neutral wire required: No
- Dimming technology: Trailing edge phase-cut dimming
- Minimum load without neutral: 20W
- Shelly Bypass support: Yes, recommended for low-power LED light sources
- Number of outputs: 1 dimmable lighting circuit
- Switch inputs: 2, S1 and S2
- Maximum output power: 200W
- Maximum output current: 0.85A
- Dimmable LED load: Maximum 150W
- Incandescent lamp: Maximum 200W
- Halogen lamp: Maximum 200W
- Dimmable electronic transformer: Maximum 200W
- Iron-core transformer: Maximum 200VA
- Power metering: Yes, when wired with neutral
- Voltage measurement: 180–280V AC
- Current measurement: 0–3A
- Internal temperature sensor: Yes
- Overheating protection: Yes
- Overcurrent protection: Yes
- Overvoltage protection: Yes, when wired with neutral
- Undervoltage protection: Yes, when wired with neutral
- Overload protection: Yes, when wired with neutral
- Dimensions: 38.5 × 43.5 × 17 mm
- Weight: 24.3 g
- Installation: Flush-mounted wall box
- Recommended wire cross-section: 0.5–4 mm²
- Wire stripping length: 5–6 mm
- Maximum terminal torque: 0.4 Nm
- Operating temperature: -20°C to +40°C
- Humidity: 30–70% RH
- Maximum installation altitude: 2000 m
- Wi-Fi: IEEE 802.11 b/g/n/ax, 2.4 GHz
- Bluetooth: Bluetooth 5 LE
- Zigbee: Zigbee 3.0, IEEE 802.15.4
- Zigbee Router function: Yes
- Wi-Fi range: Up to 30 m indoors and 50 m outdoors
- Bluetooth range: Up to 10 m indoors and 30 m outdoors
- Zigbee range: Up to 100 m indoors and 300 m outdoors
- Processor: ESP-Shelly-C68F + STM32G051
- Flash memory: 8 MB
- Number of schedules: 20
- Webhook support: 20 events, up to 5 URLs per event
- MQTT support: Yes
- JavaScript scripting: Yes
- Web interface: Yes
- API support: HTTP, HTTPS, WebSocket, RPC
