maxlength

If the value of the type attribute is text, email, search, password, tel, or url, this attribute specifies the maximum number of characters (in Unicode code points) that the user can enter; for other control types, it is ignored. It can exceed the value of the size attribute. If it is not specified, the user can enter an unlimited number of characters. Specifying a negative number results in the default behavior; that is, the user can enter an unlimited number of characters. The constraint is evaluated only when the value of the attribute has been changed.
