Use HA without internet

Hello,
For my future use of HA, I wanted to know if I could use it without internet. Indeed, in my installation I would not have internet but only a local server. Could I use HA, with Zigbee’s products without an internet connexion ? And also, could it be possible to use a tablette connected with wifi to my HA server without internet.
I know that my request is quite strange but it could really help me to know that.

Per advance thank you.

Mathis LE ROUX.

Welcome, Mathis!

If you don’t need integrations that depend on API (e.g. Weather), HA runs flawless, only WiFi is necessary.

Yes, but you don’t need to limit yourself to ZigBee.
You can use zwave or wifi (with local control) also, or even RF or possibly IR.
Perhaps there is a protocol I missed :man_shrugging:

Yes. Just set the app to connect to the local IP.

I don’t think it’s that uncommon.
Some people have HA in RVs or boats.
Although possible, I doubt you have internet to HA on a boat.

Thanks you for your answer both.

I only talked about Zigbee because I thought it could not be possible with the others. But for example, could I use Govee products (work with wifi) without internet ?

I did not think that HA could be use in boats. Good anecdote thanks.

I don’t own any Govee products myself so I can’t comment on that.
I was more thinking of Shelly, Tasmota, ESP-Home, etc.
But perhaps you can flash a Govee product, or perhaps it has local control. I don’t know.

Very well thank you for all your advice.

There might be a caveat with doing this. Home Assistant OS has an issue with a misconfigured CoreDNS service that will go into a fallback loop when it can’t access the internet anymore and progressively start spamming your local network with an ever increasing amount of DNS PTR queries (that go nowhere). After a while this can grind everything to a halt due to the shear mass of queries (several per second, 24/7). I am not sure if there have been any improvements on that front over the last couple of releases, but since the devs considered this behavior a ‘feature’, all proposed PRs and bug fixes were rejected when I last followed this issue last year.

Something to keep in mind and do additional research on if your primary deployment situation is offline. Only HA installation methods with a supervisor are (or at least have been) affected by this. HA container or core are not.

I used to run HA core on my boat for a while and it ran fine. I’ve removed it since, but for other reasons.