[mseebach]

I used to stay a lot at a hotel that would "helpfully" exempt a good number of domains from the captive browser, including whatever macs and androids use to detect connectivity...

There should really be a standard for dealing with this, like a flag on DHCP saying "O HAI you need to login here", and providing a REST endpoint that will tell the OS the status of the connection at any given time.

[praseodym]

As if such a standard would help for these WiFi providers that explicitly take steps to avoid captive portal detection?

[nsgi]

Surely it's not in their interest to avoid captive portal detection, anyway? After all, it helps them advertise their product!