Jquery Max character with character count for input and textarea
There are a few things I would suggest:
1. Replace you numbers with constants and revert the condition to get rid of 'else':

var minTextLength = 0;
var maxTextLength = 5000;
if (maxCharLength &gt;= minTextLength || maxCharLength &lt;= maxTextLength){
      //Your code...
    }


2. Move the block of code:

$(this).next("span").html('&lt;strong&gt; Maximum of ' + maxCharLength + ' characters used.&lt;/strong&gt;');
            $(this).next("span").addClass("red");
        } else { $(this).next("span").removeClass("red"); }


To a separate function.

And there are a couple of things that confuse me:
1. In 'Max Length textarea' you have:

$('textarea[maxlength]').keyup()


Is it correct? Becasue it means that you'll add a lot of handlers to all your textarea[maxlength].

2
. In your 'Max Length Input' you have:

if(charLength == maxCharLength )


Maybe it could be replaced with:

if(charLength &gt; maxCharLength )


Depending on the answers to these questions, maybe it'll be possible to move the keyup  handler to a separate function. And maybe even the whole code from both 'Max Length textarea' and 'Max Length Input'.