Google is about to roll out a change on Android that changes how captive portals are opened.
Tip: I never connect to open Wi-Fi networks because of security and privacy concerns. I do use the option to create instant hotspots on Android using my mobile device when possible, which is much safer. Clearly, this works only if you do have mobile coverage on Android.
Good to know: Captive Portals are webpages that are displayed by public wireless networks before Internet access is granted.
The change moves Captive Portal entry pages from being displayed using Android WebView to Android Custom Tabs.
The main benefit of the change is that saved passwords, autofill data and session data becomes available from the default system browser; this may benefit users who sign-in to specific portals regularly.
Some portals may ask users to sign-in to social media accounts or share personal data. This may be cumbersome without autofill support, and the update changes that.
So, if you trust a public Wi-Fi, you may now sign-in faster, if it asks for login data or personal information.
Note that the change is not enabled yet according to Android Authority.