Shelly 1L Gen4

Device identification

• Device name: Shelly 1L Gen4

• Device model: S4SW-0A1X1EUL

• Device SSID: Shelly1LG4-XXXXXXXXXXXX

• Device Bluetooth ID: 0x1035

Short description

Shelly 1L Gen4 (the Device) is a compact single-channel smart switch tailored for lighting control. A standout feature of this device is that it doesn't require a Neutral wire to operate. However, it needs a Shelly Bypass 1L/2L Gen4 connected in parallel to the load. Shelly 1L Gen4 allows users to effortlessly control their lighting setups through a mobile phone, tablet, PC, or integrated home automation system.

The Device can function standalone within a local Wi-Fi network or can be integrated with cloud home automation services. As long as the Device remains connected to a Wi-Fi router and the Internet, users can access, control, and monitor their lighting configurations from virtually anywhere.

Designed with adaptability in mind, Shelly 1L Gen4 is engineered to snugly fit within standard electrical wall boxes, be discreetly placed behind light switches, or in other areas where space might be a limiting factor. An added benefit is its embedded Web Interface, which allows users to not only monitor and control their lighting but also to fine-tune the Device settings with ease.

The Device has a multi-protocol wireless MCU which provides Zigbee and Bluetooth connectivity ensuring a secure connection.

This Device is compatible with Matter.

Main features

• Perfect to retrofit! No need for a neutral wire. You can power and control your light, or other appliances using just a live wire, with no necessity to connect a neutral wire to the device.

• No minimum load. The device requires a Bypass to be installed next to the light, however, that allows it to control any load - no more minimum load required.

• Wi-Fi Connectivity: Shelly 1L Gen4 connects to your home Wi-Fi network, allowing you to control it remotely through the Shelly mobile app or other smart home platforms.

• Zigbee Connectivity: Shelly 1L Gen4 connects to your Zigbee network, allowing you to control it remotely through the smart home automation platforms.

• Matter Connectivity: Shelly 1L Gen4 connects using Matter connectivity to your smart home automation platforms, allowing you to control it remotely through the ecosystem.

• Remote Control: You can remotely control the connected device or appliance from anywhere with an internet connection using the Shelly app on your smartphone or tablet.

• Voice Control: If integrated with voice assistants like Amazon Alexa or Google Assistant, you can control the device using voice commands.

• Scheduling and Automation: Shelly 1L Gen4 supports scheduling and automation, enabling you to set timers and create routines for your connected devices. For example, you can schedule lights to turn on and off at specific times.

• Compatibility:

  • It is designed and tested to ensure compatibility with wide range of lights.

  • It is designed to work with wide ranges of voltages - 110-240 VAC (Note: 110 V version requires different type of Shelly Bypass)

• Compact Design: Shelly 1L Gen4 has a compact design, allowing it to fit into electrical boxes or behind switches without taking up much space.

• Protection: Internal temperature sensor for overheating protection

• Local and Remote Access: You can control your devices both locally when connected to the same Wi-Fi network and remotely when you're away from home.

• OTA Updates: Shelly devices often receive over-the-air (OTA) firmware updates to enhance functionality and security.

• Compatibility with Smart Home Ecosystems: Shelly 1L Gen4 may be compatible with various smart home ecosystems and platforms, such as MQTT, Home Assistant, and more, making it a versatile choice for building a smart home.

• New features as compared with the old Shelly 1L: All of the new features coming with the new Shelly devices - Scripting support, HTTPS, MQTTS, Inbound and Outbound Web Sockets, Matter and Zigbee connectivity.

Use cases

1. Remotely control and automate lighting or electrical devices in your home using the Shelly app or voice assistants.

2. Install the 1L Gen4 in wall switches or limited spaces, making it suitable for various electrical installations.

3. Use the internal temperature sensor for overheating protection to ensure safety.

4. Set schedules to turn lights on and off based on sunrise and sunset times for energy savings and security.

5. Enjoy compatibility with various third-party smart home systems like Home Assistant, Google Home, Alexa, and SmartThings.

6. Ensure that lights are not left on by automating the switching off of lights.

7. No need for rewiring, making it a suitable option even for older electrical systems.

8. Retrofit your existing switches, making it possible to control lights with normal single buttons.

9. Manage lights and fans remotely from your smartphone or tablet.

10. Combine multiple 1L Gen4 units for controlling and automating different parts of your home.

Main applications

• Residential

• MDU (Multi Dwelling Units - apartments, condominiums, hotels, etc.)

• Light commercial (small office buildings, small retail/restaurant/gas station, etc.)

• Government/municipal

• University/college

Integrations

Simplified internal schematics

Device electrical interfaces

Inputs

• 2 switch/button inputs on screw terminals: S1 and S2

• 1 power supply input on screw terminal: L

Outputs

• 1 switch/button signal output on screw terminal: Sx

• 1 relay output on screw terminal: O

Connectivity and protocols

• Wi-Fi

• Bluetooth

• Zigbee

Safety function

• Overheating protection

• Overcurrent protection

Supported load types

• Incandescent lights*

• LED lights*

*without step-down transformers for lower-voltage lights

User interface

Inputs

• One (Control) button

  • Press and hold for 5 seconds to enable Device access point and Bluetooth connection.

  • Press and hold for 10 seconds to factory reset the Device.

  • Press the button 5 times to switch the Device from Matter (default) to Zigbee profile. The Device enters inclusion mode for 3 minutes. Include the Device following the instructions of your Zigbee home automation system.

  • Press the button 3 times to restart the inclusion mode for another 3 minutes if you missed the previous 3-minute window.

Outputs

• LED (monocolor) indication

  • AP (Access Point) enabled and Wi-Fi disabled:
    1 second ON / 1 second OFF

  • Wi-Fi enabled, but not connected to a Wi-Fi network:
    1 second ON / 3 seconds OFF

  • Connected to a Wi-Fi network:
    Constantly ON

  • Cloud is enabled, but not connected:
    1 second ON /5 seconds OFF

  • Connected to Shelly Cloud:
    Constantly ON

  • OTA (Over the Air Update):
    ½ sec ON / ½ second OFF

  • Button pressed and held for 5 seconds:
    ½ second ON / ½ second OFF

  • Button pressed and held for 10 seconds:
    ¼ second ON / ¼ second OFF

The list above starts with the initial device status and the lowest priority. Every next state cancels the previous one.

Specifications

Basic wiring diagrams

Legend

Components and APIs

• This device

• All Shelly devices and services

Compliance

• Shelly 1L Gen4 multilingual EU declaration of conformity 325 2026-09-10.pdf

• Shelly 1L Gen4 UK PSTI ACT statement of compliance 325 2026-09-10.pdf

• Shelly 1L Gen4 UKCA declaration of conformity 325 2026-09-10.pdf

Printed user guide

• Shelly 1L Gen4 multilingual printed user and safety guide.pdf