I’ve heard Zigbee groups ensure your lights all act in sync when turning on or off.
Thing is, I haven’t noticed any difference between the areas I have Home Assistant groups vs Zigbee groups. I even tried in my dining room with 4 Zigbee lights (one is the wall switch’s LED indicator strip). I clicked a whole bunch in the brightness values, and they all stay in sync no problem.
They’re not native to Home Assistant
One reason I don’t like Zigbee groups is they aren’t first-class citizens. If I click the group in Home Assistant, it doesn’t bring me to the Zigbee groups menu.
Maybe my mesh is good?
I also have over 150 Zigbee devices with at least 100 being routers in addition to using the new ZBT-2 as my coordinator.
What am I missing? Are Zigbee groups really that good or is this old knowledge that no longer matters?
The advantages include less network traffic (one command to the group instead of one command to each member), and it’s also good to use for binding (which is great for being non-dependent on the Zigbee coordinator).
In a nutshell they can (if you have the right hardware) provide functionality not available in Home Assistant.
Specifically:
Function without HA (or when HA is down) some switches/dimmers can be grouped so that they function even without HA.
Synchronous changes - sometimes you can see a small delay as HA turns on a large group of lights, if they are grouped typically all changes will happen at the same time.
No Flash - Some lights briefly flash the prior color when activating a HA Scene (and don’t with Zigbee scenes) - this is very manufacturer dependent.
I briefly tinkered with Zigbee groups but I found inconsistencies between manufacture implementations to make them a pain to use, so I went back to HA Scenes.
If one of the above list really bugs you, then you might want to play with them, otherwise there probably isn’t a big win.
Can you give me a rundown of binding and how that can help?
I’m assuming it ties your device to the switch itself, but then I lose Home Assistant control that way. Yes, it works without Home Assistant, but that’s not necessarily a good thing.
I believe you lose the ability to disconnect functionality - i.e. if a switch and a light are grouped the switch will always activates the light where as if you use an automation in HA you can add a condition to break the connection in some cases.
But this means all my custom key commands 'n such wouldn’t run through the automation. It has a 1:1 binding of the lights with the button and whatever that button was programmed to do, not how I programmed it in Home Assistant. That’s what I mean.
Syncing
I don’t have syncing issues, but like you said, it might be so minor, I don’t notice.
I remember getting “too many messages” errors with the ZBT-1 but not with the ZBT-2.
Flashing colors
Never seen this before, but I only have Philips Hue and some IKEA Tradfri Zigbee lights.
Zigbee Groups
Yeah, I have a bunch of groups, but I don’t like 'em.
The groups are improved?
Ok… I’m actually fine with Zigbee groups if they look like this in Home Assistant now:
I don’t think this was the case until 2026.4. I don’t remember being able to go into a Zigbee group to see its members like a regular Home Assistant Group until just now.
But I still don’t like how you create the group through this awkward menu with very basic UI:
It’d be neat if Home Assistant could do this for you using the Group helper integration in a way that you didn’t have to manage the groups themselves by hand.
No, it’s the same principal in ZHA, it’s a Zigbee feature not a Z2M feature. It’s not something mandatory, but it’s a nice feature to be able to use your lights even if HA is down.
I wasn’t able to test this functionality - I don’t currently have any buttons/switches that support grouping/binding, but my understanding is the same as yours.
In my reading the switch sends commands directly to a Zigbee group (thats why I called it grouping not binding) however as noted, I may be off base here since I haven’t been able to test this myself.
I have a mix of bulbs Philips Hue bulbs do not have the flash issue Aqara and Sengled do - I don’t have any IKEA bulbs to test.
Man, I had no clue. This is important to know before purchasing. I will avoid Zigbee-flash brands like those. Not that I’d have a need. I have 2 bins full of spare smart bulbs I can use.
Meh, as a rule of thumb you get what you pay for (I can get 4 bulbs for 1 Hue bulb) and there are use cases - such as bulbs in closets where I don’t care about:
The flash
Color acuracy
Brightness
Zigbee group/scene support
Difficulty of adoption / removal from network / reseting.
Zigbee router support/strengh
…
I don’t really regret any of the bulbs I have purchased - but you can also see that as a statement that there aren’t any clear winners or losers.
If price was no object, I would probably only have Hue bulbs** - but it is “an object” so I am happy with the mix.
** - Others have had incredible difficultly resetting Hue bulbs - but I haven’t hit that issue myself having moved them between 3 Zigbee networks (over time).
Since I’ve gotten my answer, I don’t mind going a little off-topic here .
Reset Hue Bulbs
Yes, resetting Hue bulbs without the Hue Bridge is insane. I bought a few Philips Hue buttons to help reset them because apparently that’s the only way. I’ve never got it to work though.
If use use their bridge, it’d be super easy, but who wants to do that? My Zigbee mesh has over 150 devices. Breaking that into 2+ networks is gonna be bad.
Cheap lights
I have a ton of LIFX lights since 2016 (hundreds, literally). They used to be better at color and brighter than Hue, and they were always cheaper. Not the case in 2026.
It’s all thanks to Home Assistant that I can now mix LIFX ($20), Philips Hue ($50), and IKEA Tradfri ($10). For 7 years, I was stuck with one light brand because I had to write my own code. Home Assistant is incredible!
Well this is news! It sounds like you don’t want to use groups because it’s like a multicast Ethernet packet rather than a directly-switched packet to that one device. Every device in the mesh gets the message rather than only those specific ones.
To me, that seems like a huge disadvantage to using Zigbee groups. I’ll have to research this more.
A large number of small groups is probably going to less efficient than using unicast messages, however if you have very large groups multicast may be more efficient.
What would you consider a “very large” group? Mine are 2-4 lights each. If these multicast messages really hit every device, I need to stop that. I can’t imagine that’s good for the battery life of my end devices either right?
I’m surprised. I always thought this determined one device as the “host” and sent the group message to it and had it replicate that to others in the group nearby.
I would need to go through the previous specification in detail to ensure I have understood all the nuances, however my “rough” theory is:
Broadcast
A broad cast message will be sent once by all routers in your network so if you have N routers there would be a total of N + 1 (including the co-ordinator) total transmissions.
Unicast
There will be a route/path between the coordinator and the final device assuming the average path is H hops long and your group had D devices then the total number of message transmissions would be H * D.
Summary
So given you have:
N - routers in your Zigbee network.
H - Hops on average to get a device from the coordinator.
Then it would be more efficient (minimize total transmissions) to use Zigbee groups, if the group you were addressing contains at least:
(N + 1) / H devices.
So in my case:
(22 + 1 ) / 3 ~= 8 devices - which is around 1/6 of my Zigbee devices.
Likewise, I wish I’d known this. Appreciate you both digging into it.
Before I make changes, @dtrott how certain are you about your theory? And where might I work out the average hops to a path? Is that just by looking at the map?
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