Ask HN: Why have login forms been split into two steps?

This allows customized flows based on username/email. From what I've seen, there are mostly two use cases 1. different flows based on organization e.g. Microsoft Office 365 2. different flows based on guest vs user so the website can capture the emails if it's not a registered user e.g. tumblr

Makes sense thanks

> It breaks autofill from a browser password manager extension

That is the benefit, just not for the user. The companies that started this trend were generally single sign-on providers that want you to sign in to everything with their account so you can be tracked everywhere on the web, services like 1Password make this unnecessary. The rest I think are just cargo-culting the big players.

- Sites that do single sign on: your email domain is 'corp.example.com'? -> redirect to your org's sign in page.

- Mandatory 2FA/etc