Best Zigbee and Thread Dongles for Home Assistant

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The radio dongle is the cheapest part of a Home Assistant build and the part people most often get wrong. It is a stick that costs a rounding error next to the machine it plugs into, and yet picking the wrong one is how you end up with sensors that drop off every few days and a mesh you spend a month blaming.

The mini PC buying guide for Home Assistant covers the host. This page covers the radio: which dongle to buy, what the chip inside it actually decides, and the placement mistake that causes most of the “my Zigbee network is flaky” threads.

Everything here is researched from manufacturer specifications and the Zigbee2MQTT supported adapters documentation, not measured on a bench.

The one decision that matters: which chip is inside

Forget the brand on the case. There are effectively three chip families in this market, and the family sets what the stick can do.

Silicon Labs EFR32, the MG21 and MG24 series. These run Zigbee or Thread. If there is any chance you will want Thread, which is the radio layer under most Matter battery devices, you need this family. Home Assistant’s own Thread border router support is built on it.

Texas Instruments CC2652 and CC2674. Zigbee only, in the context of Home Assistant. Mature, extremely well supported, and the family the Zigbee2MQTT community has leaned on longest. The letter at the end of the part number matters: a chip ending in P has a power amplifier good for up to 20dBm, while the R and RB variants top out around 5dBm.

Dresden Elektronik deCONZ, the ConBee sticks. Their own firmware stack. Still listed as supported, but with real caveats covered below.

Two consequences fall out of that split, and they are the useful part:

• Only zStack and EmberZNet adapters support a coordinator backup. Zigbee2MQTT writes a coordinator_backup.json for those two families and not for deCONZ. That file is what lets you move your network to a new stick later without re-pairing everything.
• One radio network per stick. The combined Zigbee-and-Thread mode, multiprotocol or MultiPAN, has quietly been abandoned. Nabu Casa says the ZBT-2 cannot do both at once, and the Zigbee2MQTT docs say multiprotocol firmware is not supported and recommend one adapter per protocol. Budget for two sticks if you want both.

The shortlist

Dongle	Chip	Zigbee or Thread	Antenna	Notes
Home Assistant Connect ZBT-2	Silicon Labs MG24	Either, one at a time	External, on a weighted base	Official hardware. 460800 baud, hardware flow control, one-click updates
SONOFF Dongle Plus MG24	Silicon Labs MG24	Either, one at a time	External, 3dBi	Same chip generation, sold on Amazon. Software flow control only
SONOFF ZBDongle-E	Silicon Labs MG21	Either, one at a time	External, SMA	The older Silicon Labs option. Flash newer firmware than the bundled PDF suggests
SONOFF ZBDongle-P	TI CC2652P	Zigbee only	External, SMA	The long-standing community default. Ships pre-flashed, 20dBm
SMLIGHT SLZB-07	Silicon Labs MG21	Either, one at a time	External	Compact, and supports hardware flow control
SMLIGHT SLZB-06M	Silicon Labs	Either, one at a time	External	Ethernet with PoE instead of USB. Solves placement outright
ConBee III	deCONZ	Zigbee	Internal	Works, but no coordinator backup and no Touchlink

Prices on these move around and the cheap end of the market churns constantly, so check the current price on whichever one you shortlist rather than trusting a figure in an article.

What to buy

If you are starting fresh and want to stop thinking about it: the ZBT-2. It is the official Nabu Casa adapter, so firmware updates arrive through Home Assistant itself rather than through a flashing tool and a forum thread. The MG24 chip is the current generation, the serial link runs at 460800 baud instead of the ZBT-1’s 115200, and the antenna sits on a weighted base on a USB-C cable, which means the radio is already away from your machine without you buying anything extra. Note that it is sold through Home Assistant’s own store and its retail partners, not on Amazon, so that link goes to Nabu Casa.

If you want the same chip generation on Amazon: the SONOFF Dongle Plus MG24. Same MG24 family, external 3dBi antenna, and widely stocked. One configuration detail that will cost you an evening if you miss it: this stick supports software flow control only, so do not set rtscts: true in your Zigbee2MQTT adapter config. The ZBT-2 and the SLZB-07 do support hardware flow control and do want that flag.

If you only want Zigbee and you want the safest cheap pick: the SONOFF ZBDongle-P. TI CC2652P, pre-flashed with Z-Stack coordinator firmware, external SMA antenna, and a 20dBm output stage. This has been the default recommendation in Zigbee2MQTT circles for years for a reason. You are giving up any future Thread option, and that is the entire tradeoff. Be careful when ordering: SONOFF sells both a “Dongle Plus” ZBDongle-P and a “Dongle Plus” ZBDongle-E, the listing titles are nearly identical, and the chips are from different families. Read the chip in the listing text, not the product name.

If the dongle cannot physically go anywhere good: the SMLIGHT SLZB-06M. This is an Ethernet adapter with PoE rather than a USB stick, so the radio goes wherever your network cable goes and nowhere near the server. If your homelab lives in a closet, a basement, or a rack in the garage, and your sensors do not, this is the honest fix rather than a mesh problem to solve with repeaters. One caution from the Zigbee2MQTT docs: prefer wired Ethernet over the WiFi mode, because the serial protocol does not tolerate the packet loss and latency WiFi introduces.

I would skip the ConBee as a first dongle. It works, and the ConBee III is the current model, but the documented limitations stack up: no coordinator backup, so a later migration means re-pairing; no Inter-PAN support, which rules out Touchlink; and transmit power cannot be lowered. The older ConBee II also has reported connectivity issues. None of that is disqualifying if you specifically want deCONZ and the Phoscon app, but it is a lot of asterisks on a purchase where two better-supported families cost about the same.

What happened to the ZBT-1 and SkyConnect

If you have been reading older guides, you have seen the Home Assistant SkyConnect, later renamed the Home Assistant Connect ZBT-1. It is discontinued. Nabu Casa replaced it with the ZBT-2 and says so plainly on the product page.

The generational differences, from Nabu Casa’s own comparison:

	ZBT-1	ZBT-2
Zigbee and Thread chip	Silicon Labs MG21	Silicon Labs MG24
USB chip	Silicon Labs CP2102N	ESP32-S3
Serial baud rate	115200	460800
Antenna	Small, internal	External, on a base
Opening the case	Hard	No clips or glue, exposed pads and pins

If you already own a ZBT-1, keep using it. It is still a supported EmberZNet adapter, your network is fine, and the upgrade buys you a better antenna and a faster serial link rather than a capability you are missing. If you are buying today, there is no reason to hunt down old stock, and plenty of third-party listings now advertise themselves as “compatible with Connect ZBT-1” rather than being the real thing.

Placement beats every spec on this page

This is the part that decides whether your network is reliable, and it costs almost nothing.

A 2.4GHz radio plugged directly into the back of a mini PC is sitting in a noise field. USB 3.0 controllers and ports are well documented emitters in that band, and a compact chassis puts the NVMe drive and the power supply right there too. The symptom is not a dead network. It is devices that drop off every few days, pairing that works on the bench and fails across the house, and a creeping suspicion that Zigbee is just flaky.

Three things, in order of how much they buy you:

1. Put the stick on a USB extension cable. A 10ft USB 3.0 extension cable is the cheapest reliability upgrade in the build. Even a short one helps. Route it away from the machine and up off the floor if you can.
2. Get the antenna into open air. This is where the external-antenna sticks earn their premium over the internal-antenna ones, and where the ZBT-2’s weighted base is doing real work rather than looking nice.
3. Add mains-powered Zigbee devices as routers. A Zigbee mesh extends itself through any plugged-in device. Smart plugs and bulbs are repeaters. Battery sensors are not and never will be.

Do all three before you conclude you bought the wrong dongle. Most “I need a better coordinator” posts are placement problems.

Running it on a Proxmox host

If Home Assistant is a VM on a Proxmox box rather than a bare-metal install, the dongle has to be handed through to the guest. That is a config change, not a project, and it is covered in the Proxmox USB passthrough guide.

Two things worth knowing before you get there. Pass the device through by its persistent /dev/serial/by-id/ path rather than /dev/ttyUSB0, because the numbered device can move between reboots and take your Zigbee integration with it. And HAOS needs a full VM, not a container, which is the practical reason most people land on the VM route in the first place. The VM versus LXC comparison covers that split, and the Home Assistant on a mini PC walkthrough runs the whole install end to end.

The short version

Buy a Silicon Labs EFR32 stick unless you are certain you will never want Thread. The ZBT-2 if you want official hardware and in-app firmware updates, the SONOFF Dongle Plus MG24 if you want the same chip generation from Amazon, the ZBDongle-P if Zigbee-only is a decision you are happy to commit to, and the SLZB-06M if the server and the sensors live in different parts of the house. All four are linked in the table above.

Then spend a few dollars on an extension cable, plan on one stick per radio protocol, and put a couple of mains-powered Zigbee devices in the middle of the house. That combination matters more than which of the shortlist you picked.