This will take slightly more characters but not many.

I went about updating my profile bio on Twitter the other day.  The print that I ignored underneath the text entry field says the limit is 160 characters. So I type in my bio, click save, and receive the following (crudely) written error message:

I suppose I am guilty of ignoring the small print. That aside, I don’t have an inbuilt character meter that alerts me when I am approaching character 159.

If I were designing this functionality, I would do the following.

Place the character limit number to the top right of the form field and as the user types count it down to 0. When a user exceeds this limit I would then change the colour of the excess character number to red.

Look familiar ??