Home Assistant Connect ZBT-2

Official Zigbee and Thread Hardware Built for Home Assistant

What is the Home Assistant Connect ZBT-2?

The Home Assistant Connect ZBT-2 is the official second-generation USB radio adapter for connecting Zigbee or Thread devices directly to Home Assistant. Designed by Nabu Casa and the Open Home Foundation ecosystem, it combines a Silicon Labs MG24 radio with a high-performance omnidirectional antenna and an ESP32-S3 USB controller.

Connect ZBT-2 supports Zigbee 3.0 or Thread, allowing it to connect Zigbee devices directly through integrations such as ZHA and Zigbee2MQTT, or operate as the Thread radio for Matter-over-Thread devices. The adapter must be dedicated to either Zigbee or Thread at one time and does not run both protocols simultaneously.

Key Takeaways

• Official Home Assistant hardware
• Second-generation replacement for Connect ZBT-1 / SkyConnect
• Silicon Labs MG24 Zigbee and Thread radio
• ESP32-S3 USB-to-serial controller
• Zigbee 3.0 support
• Thread support
• Matter-over-Thread support through Home Assistant
• Works with ZHA
• Works with Zigbee2MQTT
• Works with OpenThread Border Router
• Works with Matter.js
• Optimized external antenna
• 4.16 dBi peak antenna gain
• Omnidirectional antenna pattern
• 460800 baud communication
• USB-C connection
• One-click firmware updates
• Zigbee and Thread network migration support
• Designed for local smart-home control
• Open and accessible hardware design

Built Specifically for Home Assistant

Unlike a generic Zigbee USB dongle, Connect ZBT-2 was developed specifically for the Home Assistant ecosystem.

The same wider Home Assistant development ecosystem responsible for technologies such as:

• Home Assistant
• ZHA
• Matter.js
• Thread integration

also contributed to the design and software experience surrounding Connect ZBT-2.

The result is a radio adapter designed to provide straightforward setup, firmware updates and migration directly within Home Assistant.

Connect it to your Home Assistant system through USB-C, follow the setup wizard and dedicate the adapter to either a Zigbee or Thread network.

Direct Zigbee Control Without a Manufacturer Hub

One of the biggest advantages of the Home Assistant Connect ZBT-2 is that compatible Zigbee devices can communicate directly with Home Assistant.

Instead of:

Zigbee Device → Manufacturer Hub → Cloud → Home Assistant

you can create a setup such as:

Zigbee Device → Connect ZBT-2 → Home Assistant

This can reduce your dependence on manufacturer-specific gateways and cloud services.

Compatible Zigbee devices can include:

• Motion sensors
• Door and window sensors
• Temperature sensors
• Humidity sensors
• Smart plugs
• Smart switches
• Buttons
• Smart bulbs
• Presence sensors
• Water leak sensors
• Smoke detectors
• Heat detectors
• Other Zigbee-certified accessories

Actual functionality depends on support for the individual device in your selected Zigbee integration.

Silicon Labs MG24 Radio

At the heart of the Connect ZBT-2 is the Silicon Labs MG24.

This replaces the Silicon Labs MG21 used by the first-generation Connect ZBT-1.

The newer radio platform provides improved performance and sensitivity for weaker signals, making it better suited to demanding Zigbee and Thread installations.

For users upgrading from older Home Assistant hardware, this is one of the most significant internal improvements in the ZBT-2.

Optimized External Antenna

The Connect ZBT-2 looks very different from a conventional USB Zigbee dongle because its antenna is a major part of the design.

The antenna measures approximately:

24 mm diameter × 164 mm high

with a specified peak gain of:

4.16 dBi

and an:

Omnidirectional radiation pattern

The larger antenna system is intentionally designed to improve 2.4 GHz Zigbee and Thread performance.

Its base also allows the radio to be positioned away from the USB port of the Home Assistant host rather than placing the Zigbee radio directly beside the computer.

Designed to Reduce USB Interference Problems

USB-connected Zigbee coordinators can experience interference when positioned close to computers, SSDs, USB 3.0 devices and other electronics.

The ZBT-2 uses a separate antenna and base connected through an included 1.5-meter USB-C cable.

This allows you to position the radio away from potential sources of interference and place it in a more suitable location for Zigbee or Thread coverage.

Good placement remains important even with a high-performance antenna.

For best results, avoid positioning the adapter:

• Behind large metal objects
• Directly beside Wi-Fi routers
• Inside metal cabinets
• Next to USB 3.0 storage devices
• Beside large electronics
• On the floor
• In enclosed spaces

A more central and elevated position will generally provide a better starting point for a smart-home radio network.

Zigbee 3.0 Support

Connect ZBT-2 supports Zigbee 3.0.

When configured for Zigbee, it acts as the radio connecting your Home Assistant system to compatible Zigbee devices.

This allows you to build your own Zigbee mesh using Home Assistant rather than depending on a manufacturer-specific gateway.

Powered Zigbee router devices can then help expand the mesh throughout your property.

Common Zigbee routers include compatible:

• Smart plugs
• In-wall switches
• Dedicated repeaters
• Powered lighting products

Battery-powered sensors normally operate as end devices and do not extend the Zigbee mesh.

Works with ZHA

Connect ZBT-2 is designed to work directly with ZHA, Home Assistant's native Zigbee integration.

ZHA allows compatible Zigbee devices to be paired and controlled directly from Home Assistant.

A typical setup becomes:

Zigbee Devices → Connect ZBT-2 → ZHA → Home Assistant

This provides a straightforward option for users who want Zigbee functionality integrated directly into Home Assistant without installing a separate Zigbee management platform.

Works with Zigbee2MQTT

The Home Assistant Connect ZBT-2 also works with Zigbee2MQTT.

This gives users the flexibility to choose between ZHA and Zigbee2MQTT rather than being locked into a single Zigbee software platform.

A Zigbee2MQTT installation typically works as:

Zigbee Devices → Connect ZBT-2 → Zigbee2MQTT → MQTT → Home Assistant

Home Assistant states that Connect ZBT-2 is already being used successfully with Zigbee2MQTT and points users to Zigbee2MQTT's adapter migration documentation when moving an existing network.

Thread Support

Connect ZBT-2 can alternatively be dedicated to Thread.

Thread is an IP-based low-power mesh networking protocol used by many newer smart-home products.

When configured appropriately within Home Assistant, the ZBT-2 can provide the Thread radio needed for compatible Thread devices and Matter-over-Thread accessories.

This makes the same hardware useful for users building either a traditional Zigbee network or a newer Thread-based smart home.

Matter-over-Thread Support

Matter itself is not the radio protocol used by the ZBT-2.

Instead, some Matter devices communicate over Thread.

In that configuration:

Matter Device → Thread → ZBT-2 / Thread Network → Home Assistant Matter Integration

Home Assistant is Matter certified and supports Matter devices using both Wi-Fi and Thread.

The ZBT-2 becomes relevant specifically when a Matter device communicates over Thread.

Important: Choose Zigbee or Thread

The Connect ZBT-2 supports both Zigbee and Thread, but not simultaneously.

You must dedicate the adapter to either:

Zigbee

or

Thread

Home Assistant specifically does not recommend multiprotocol or MultiPAN operation for the ZBT-2.

This means you should not purchase one ZBT-2 expecting it to run your Zigbee network and your Thread network at the same time.

If you need dedicated Zigbee and Thread radios simultaneously, use separate hardware for each network.

Faster Communication Than ZBT-1

The first-generation Connect ZBT-1 used a serial communication rate of:

115200 baud

Connect ZBT-2 increases this to:

460800 baud

That is a 4× increase in adapter communication speed.

Home Assistant states that this improvement consistently helps improve device responsiveness.

Connect ZBT-2 vs Connect ZBT-1

The ZBT-2 is the official successor to the first-generation ZBT-1, which was previously known as Home Assistant SkyConnect.

Easy Network Migration

Existing Home Assistant users do not necessarily have to rebuild their Zigbee network from scratch when moving to ZBT-2.

Home Assistant provides migration tools designed to move an existing Zigbee or Thread network to a new adapter.

This can make upgrading from:

• Connect ZBT-1
• Older Zigbee coordinators
• Other supported adapters

considerably easier than manually resetting and re-pairing every device.

Migration availability and procedure depend on the integration and adapter being replaced.

Plug-and-Play Home Assistant Setup

Connect ZBT-2 is designed to minimize the complexity normally associated with configuring a Zigbee or Thread coordinator.

Connect the adapter to the Home Assistant host through USB-C and Home Assistant can guide you through the initial configuration.

The official workflow includes:

• Device discovery
• Setup wizard
• Protocol selection
• Network creation
• Migration options
• Firmware updates

This makes the ZBT-2 suitable for both new Home Assistant users and experienced smart-home enthusiasts.

Technical Specifications

Compatibility

Connect ZBT-2 is primarily designed as a dedicated Zigbee or Thread radio for Home Assistant rather than a standalone smart-home hub.

What Devices Work with Connect ZBT-2?

When operating as a Zigbee coordinator, the ZBT-2 can be used with supported Zigbee devices such as:

• Philips Hue devices
• IKEA Zigbee devices
• Aqara sensors
• SONOFF Zigbee devices
• Smart plugs
• Smart switches
• Door sensors
• Motion sensors
• Temperature sensors
• Smart lights
• Buttons
• Water leak sensors
• Other Zigbee-certified devices

When dedicated to Thread, it can help Home Assistant communicate with compatible Thread devices, including Matter-over-Thread accessories.

Compatibility with an individual device can depend on Home Assistant, ZHA, Zigbee2MQTT or Matter support for that particular model.

What’s Included?

• 1 × Home Assistant Connect ZBT-2 antenna and base
• 1 × 1.5 m USB-C cable
• 1 × Quick Start Guide
• 1 × Warranty and Safety Information

How to Set Up Home Assistant Connect ZBT-2

Step 1: Connect the ZBT-2

Attach the supplied USB-C cable to the Connect ZBT-2 and connect the other end to the system running Home Assistant. Position the antenna away from potential USB and Wi-Fi interference.

Step 2: Choose Zigbee or Thread

Follow the Home Assistant setup wizard and dedicate the ZBT-2 to either Zigbee or Thread. For Zigbee, configure ZHA or your preferred supported Zigbee software. For Thread, configure the appropriate Home Assistant Thread environment.

Step 3: Pair or Migrate Your Devices

Create a new network and begin pairing compatible devices, or use Home Assistant's migration tools to move a supported existing Zigbee or Thread network to the ZBT-2.

Using Connect ZBT-2 with Zigbee2MQTT

Connect ZBT-2 is a particularly useful option for users building a Zigbee2MQTT network.

Zigbee2MQTT provides broad device compatibility and exposes Zigbee devices to Home Assistant through MQTT.

The basic architecture is:

Zigbee Device

↓

Home Assistant Connect ZBT-2

↓

Zigbee2MQTT

↓

MQTT

↓

Home Assistant

This provides local Zigbee control without requiring the manufacturer's original Zigbee hub for supported devices.

Using Connect ZBT-2 with ZHA

Users who prefer Home Assistant's built-in Zigbee experience can use the ZBT-2 with ZHA.

The architecture becomes:

Zigbee Device

↓

Connect ZBT-2

↓

ZHA

↓

Home Assistant

ZHA is integrated directly into Home Assistant, making it a straightforward choice for users who do not want to manage a separate Zigbee2MQTT installation.

Using Connect ZBT-2 for Matter

Connect ZBT-2 can help connect Matter-over-Thread devices to Home Assistant when the adapter is dedicated to Thread.

It is important to distinguish between Matter and Thread:

Matter defines how compatible smart-home devices communicate and interact at the application level.

Thread is one of the network technologies Matter devices can use.

A Matter-over-Wi-Fi device does not need ZBT-2 simply because it uses Matter.

The ZBT-2 is relevant when your Matter accessory communicates over Thread.

Can Connect ZBT-2 Be Used as a Zigbee Repeater?

Yes, but not while functioning as your normal coordinator.

Home Assistant provides experimental repeater firmware that can turn the Connect ZBT-2 into a powerful Zigbee repeater.

When using the repeater firmware, the adapter should be connected to a suitable 5V USB power supply.

However, it cannot simultaneously act as your Zigbee coordinator. To return it to coordinator operation, the stock firmware must be flashed again.

Does Connect ZBT-2 Work as a Standalone Thread Border Router?

Not by itself.

Home Assistant states that Connect ZBT-2 is not designed to operate independently as a standalone Thread Border Router outside the Home Assistant environment.

Its Thread functionality is intended to work as part of a Home Assistant installation.

Open Hardware Design

The ZBT-2 follows the second-generation Home Assistant Connect hardware design philosophy.

The enclosure is designed to be opened without:

• Glue
• Hidden clips
• Destructive disassembly

The board also exposes useful pins and pads, making the hardware more accessible to advanced users and developers.

The ESP32-S3 USB controller further increases the platform's potential for experimentation and future development.

Placement Tips for Better Zigbee Performance

Even a high-performance coordinator benefits from good placement.

For a reliable Zigbee network:

• Use the supplied cable to move the ZBT-2 away from the host computer.
• Avoid placing it immediately beside a Wi-Fi router.
• Keep it away from USB 3.0 SSDs and hubs.
• Avoid metal cabinets.
• Position it in an open area where possible.
• Keep the antenna upright.
• Use powered Zigbee routers to build out the mesh.
• Avoid hiding the adapter behind large electronics.

Zigbee operates in the same general 2.4 GHz spectrum as Wi-Fi, so careful placement and channel planning can improve network reliability.

Pros

• Official Home Assistant hardware
• Designed specifically for Home Assistant
• Modern Silicon Labs MG24 radio
• High-performance 4.16 dBi antenna
• Omnidirectional antenna pattern
• Zigbee 3.0 support
• Thread support
• Matter-over-Thread support
• ZHA support
• Zigbee2MQTT support
• Matter.js support
• OpenThread Border Router support
• 460800 baud communication
• 4× adapter speed compared with ZBT-1
• ESP32-S3 USB controller
• Simple Home Assistant setup wizard
• One-click firmware updates
• Zigbee and Thread network migration tools
• 1.5 m USB-C cable included
• Open, accessible hardware design
• Designed for local smart-home connectivity

Cons

• Cannot operate Zigbee and Thread simultaneously
• No Z-Wave support
• No built-in Ethernet
• No built-in PoE
• Requires a Home Assistant host for its intended use
• Matter-over-Thread functionality requires dedicating the adapter to Thread

Who Should Buy the Home Assistant Connect ZBT-2?

The Home Assistant Connect ZBT-2 is particularly suitable for users who:

• Run Home Assistant
• Want to connect Zigbee devices directly
• Want an official Home Assistant Zigbee coordinator
• Use ZHA
• Use Zigbee2MQTT
• Want to remove unnecessary manufacturer Zigbee hubs
• Want to build a Thread network
• Use Matter-over-Thread devices
• Are upgrading from Connect ZBT-1 / SkyConnect
• Want a high-performance 2.4 GHz antenna
• Prefer local smart-home control
• Want straightforward firmware updates and migration

It is less suitable if you need Zigbee and Thread from the same adapter simultaneously or need Z-Wave support.

Frequently Asked Questions

What is Home Assistant Connect ZBT-2?

The Home Assistant Connect ZBT-2 is the official second-generation Zigbee and Thread USB radio adapter for Home Assistant. It uses a Silicon Labs MG24 radio, ESP32-S3 USB controller and optimized external antenna to connect compatible Zigbee or Thread devices directly to Home Assistant.

Who should buy Home Assistant Connect ZBT-2?

Connect ZBT-2 is ideal for Home Assistant users who want an official adapter for building a Zigbee network with ZHA or Zigbee2MQTT, or a dedicated Thread radio for compatible Thread and Matter-over-Thread devices.

Does Home Assistant Connect ZBT-2 work with Zigbee2MQTT?

Yes. Connect ZBT-2 works with Zigbee2MQTT. Home Assistant specifically documents Zigbee2MQTT compatibility and provides migration support for users moving from another Zigbee adapter.

Does Connect ZBT-2 work with ZHA?

Yes. Connect ZBT-2 is designed to work with ZHA, Home Assistant's native Zigbee integration, allowing supported Zigbee devices to connect directly to Home Assistant.

Does Connect ZBT-2 support Matter?

Yes. Connect ZBT-2 can be dedicated to Thread and used as part of Home Assistant's setup for compatible Matter-over-Thread devices. Matter-over-Wi-Fi devices do not require the ZBT-2 simply because they use Matter.

Can Connect ZBT-2 run Zigbee and Thread at the same time?

No. Connect ZBT-2 supports both Zigbee and Thread, but the adapter must be dedicated to one protocol at a time. It does not support simultaneous Zigbee and Thread operation.

Is Connect ZBT-2 better than Connect ZBT-1?

Connect ZBT-2 is the second-generation replacement for ZBT-1. It upgrades the radio from Silicon Labs MG21 to MG24, increases serial communication from 115200 to 460800 baud and adds a substantially larger optimized external antenna.

Can Connect ZBT-2 replace a Zigbee manufacturer hub?

For many supported Zigbee devices, yes. Compatible devices can be paired directly with Home Assistant through ZHA or Zigbee2MQTT instead of using their original manufacturer hub. Some device-specific functionality may still depend on integration support.

Why Buy the Home Assistant Connect ZBT-2?

The Home Assistant Connect ZBT-2 is designed for users who want a direct, local and officially supported way to bring Zigbee or Thread into Home Assistant.

Compared with the first-generation ZBT-1, the ZBT-2 upgrades to the Silicon Labs MG24, increases adapter communication speed to 460800 baud, adds an ESP32-S3 USB controller and uses a carefully optimized 4.16 dBi omnidirectional antenna.

For Zigbee users, it works with both ZHA and Zigbee2MQTT and can remove the need for separate manufacturer hubs for many supported devices.

For Thread users, the same hardware can instead be dedicated to a Thread network for compatible devices, including Matter-over-Thread accessories.

The important limitation is simple: one ZBT-2 runs Zigbee or Thread, not both simultaneously.