error prevention - Is it good practice to warn users that capslock is enabled when entering passwords?

Most websites that I have seen don't warn users when they type their passwords with capslock on. Given that it is possible to implement that function, why is this not a common practice?

Answer

It is not a common practice because, sadly, most of the web developers aren't actually concerned about the user experience and improving it.

One interesting approach, besides warning the user about the caps lock, is Facebook's "case insensitive" system.

Facebook actually accepts three forms of your password:

1. Your original password.


2. Your original password with the first letter capitalized. This is only for mobile devices, which sometimes capitalize the first character of a word.


3. Your original password with the case reversed, for those with a caps lock key on.