For my situation, I have a device that reports unavailable when HA restarts. Therefor, I’ve added an extra condition template to have it not trigger the automation when the state of a device changes “from unavailable”:
- condition: template
value_template: '{{ trigger.from_state.state != "unavailable" }}'
Seems to work like a charm now for me 
I have the same issue, How did you manage to solve it?
Thanky for this blueprint !
I used it to link a ZWave in-wall-switch to a Hue Zigbee ceiling lamp (complex with many lights).
Sadly, I found an error I can’t quite get behind :
Here comes the error :
Whjile this plugin works great, anyone also noticing a noticable delay between flcking a switch (not the main one but the slave one),
takes about 10-15 seconds in order to switch the other switch. Any idea how i can resolve this delya??
View the traces in your automation and check the timestamps to find where the delay is happening. Either the master switch is slow to report, or your slave switch is slow to respond.
Got it fixed.
Device causing it was an ESP32. Setting the powersafe option in ESP home to none, fixed it.
Thought it was the plugin, but my mistake. Plugin is working instantly!!
Excuses
Hello,
This is a great blueprint, thank you! One question, is there a way to still operate the switches individually? Most of the times I want all of the switches to turn on/off at the same time, but there are occasions when I would only one to turn on. Can this be achieved? (Ideally I’d like to create a ‘master’ switch for all the switches, but then also retain all the idividual switches).
Thanks
edit: just figured out i can do this with a Group Helper
Edit 2: is there a way to add Helpers to dashboard??
I use this to link a wifi wall switch with a wifi power inline on a light cord. Very simple setup.
Yesterday I had it freak out on me after turning the wall switch off and on quickly by mistake, then trying to turn it off again. They both start toggling on and off continuously for about 10 seconds. Never seen this before.
Sharing my v1.1 update with @bart_lauwers53 code and every minute background check. Nothing else changed. Source code here
Getting many errors in log from you 1.1 script (15.000 errors in 2 days).
Logger: homeassistant.components.automation
Source: components/automation/__init__.py:1006
Integration: Automatisierung ([documentation](https://www.home-assistant.io/integrations/automation), [issues](https://github.com/home-assistant/core/issues?q=is%3Aissue+is%3Aopen+label%3A%22integration%3A+automation%22))
First occurred: 18:27:00 (645 occurrences)
Last logged: 19:09:00
* Error evaluating condition in 'Link_Spüle_Alexa': In 'condition' (item 1 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 2 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 3 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 4 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'from_state'
* Error evaluating condition in 'Link_Badstreifen_Alexa': In 'condition' (item 1 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 2 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 3 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 4 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'from_state'
* Error evaluating condition in 'Link_Werkbank_Alexa': In 'condition' (item 1 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 2 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 3 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 4 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'from_state'
* Error evaluating condition in 'Link_Werkstatt_Alexa': In 'condition' (item 1 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 2 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 3 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 4 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'from_state'
* Error evaluating condition in 'Link_Unten_Alexa': In 'condition' (item 1 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 2 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 3 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'to_state' In 'condition' (item 4 of 4): In 'template' condition: UndefinedError: 'dict object' has no attribute 'from_state'
Can you tell me whats wrong here? (Links are working flawlessly)
What is the functional difference between this this other Template? Linked Entities - keep mutlple entities binary state in sync (lights, switches, etc.) - #4 by TimU
Thanks for the work on this blueprint, it’s saved me a ton of time.
I have one issue which might be my use-case but possibly someone has come across this.
I have 4 lightstrips which are part of a group.
I’ve got this blueprint syncing the group entity with the light switch entity.
This works great for turning the group on/off from the switch.
But sometimes I want to just turn on a single light strip, The issue I have is I toggle the single strip, and then will then toggle the group entity.
Without this blueprint, if i toggle a single lightstrip the entity for the group turns to “on” but the other 3 strips don’t turn on (which is ideal).
Previously i was using another blueprint: adchevrier/synchronize-the-on-off-state-of-2-entities which allowed this to work, however with this new blueprint if i toggle 1 lightstrip, it will toggle the lightswitch to ON which is expected, but then that would trigger the whole group to ON rather than just keeping the 1 lightstrip that i turned on.
Any ideas on a way to overcome this ?
Thank you so much 
There’s an option when setting up the group which lets you choose whether to show the group as on when ONE light is on, or when ALL lights are on.
Maybe that would fix your issue?
Edit: found the option. It’s called All
So in my case that setting doesn’t work as I want.
I’ve found that turning on 1 light, doesn’t toggle the light switch, but also since the light switch it paired with the group entity, turning off one light when they’re all on turns all off 
I need to somehow get it to ignore the state of the other lights if they’re toggled manually, but regardless have the light switch toggle all on/off
This blueprint is designed for two-way sync, but you’re trying to do one-way. That’s easy enough with a simple automation, when your light switch turns on, turn on all the individual lights. Switch turns off, lights turn off. The tricky bits in the code here all deal with the various problems which come up with two-way sync. One-way has no such problems, so just a simple automation should do ya.
Does not work, when used with two entities it set status of the first by the status of the second, but not other way round.
This is brilliant! I use this to run the warm water circulation pump when the lights in any of the bathrooms are on. For this I created a “binary sensor” from the on/off state of lights:
Helpers > New > Template > Binary State > Template:
{{ is_state(‘light.e1_slaapkamer1_badkamer_plafond’, ‘on’)
or is_state(‘light.e1_slaapkamer2_badkamer_plafond’, ‘on’)
or is_state(‘light.bs_wellness_douche’, ‘on’)
or is_state(‘light.bs_wellness_wastafel’, ‘on’)
or is_state(‘light.e1_master_bathroom_wastafel’, ‘on’) }}
When the light is on in any of the bathrooms the pump is ON and otherwise it’s off.
Thanks so much for this blueprint solving an issue that has caused me so much headache!
I tried again, and this bluepriont actually works, but at least with zigbee, you must not change states fast etc.
Yes, this script goes badly wrong if you quickly turn on and off a switch in the set.
The system then appears to post hundreds of messages to the other entities, and your lights flicker on and off light a bad 1970’s disco until you disable the automation.
It’s been a couple of years but I see we’re still struggling with this: Synchronize the on/off state of 2 entities - #81 by dbrand666.
This still seems to work but it hasn’t caught on: Select multiple entities to link their on/off state. If any selected entity is turned on or off, the other selected entities will be sent a matching on or off command. · GitHub.
Use my gist or just change the mode on your favorite variant to “restart” instead of “queued”.