Nothing more epic than alerting user about invalid input before they have even finished filling the field.
Over eager validation is one of my biggest gripes. Just validate the field after user has moved on to next field or has finished typing.
I read another article recently with someone else having the same gripe as yourself.
I personally like it, I think it's a nice UX touch, but I guess it's marmite functionality. Thanks for your comment.
I fully agree. It feels like someone shouting in my ear. 'wrong! wrong! wrong! oh look at this you got it right…'.
Showing proper feedback in forms is very important for the user experience (and conversion) but do it at the right time.
Please see this updated CodePen, it is any better? http://codepen.io/mjtweaver/pen/BNmrvr
I disagree. If that were the case it would be more work for the user. Imaging you input an invalid email address. Would you rather it tell you it's invalid as you type it, or after you've tabbed out of the field. This can be a pretty nasty UX, especially if the user screws up more than once. Input -> tab -> Invalid -> Click -> Input -> tab -> Invalid -> (╯°□°）╯︵ ┻━┻