Hacker News Reader

Glad you asked :)

Indicator has two states - gray and black. Gray is further animated as a visual gimmick, the actual arrangement of it has no meaning. The idea is that the animation gives you visual feedback on typing and the change of color confirms that the password is not definitively wrong. And the assumption is that after some use, the users will get accustomed to seeing black indicator immediately prior to hitting Enter.

I suspect they are matching bits.

Though since this is going through hashing, the number of matching bits has (by design) zero correlation to how close the P/W is. In which case, yeah, I think the binary indicator would be more useful and intuitive.

In particular, if you just type "qwertyuiop" or "asdfghjkl" or the like, the password looks at least as good (better, really) than when you type the correct password, right up to the last character. So, not very useful?