<!Doctype html>
<html>
<head>
<title>Twitter Style Remaining Character Count using jQuery</title>
<style>
body {
width: 610px;
}
#text-content {
padding: 10px;
border: #F0F0F0 1px solid;
border-radius: 4px;
background-color: #FFF;
}
#text-content:focus {
outline: 0;
}
#character-count {
color: #A0A0A0;
padding: 15px 0px;
}
</style>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
</head>
<textarea id="text-content" cols="70" rows="4" onKeyup="count_remaining_character()" placeholder="At least 100 character"></textarea>
<div id="character-count" align="right">150</div>
<script>
function count_remaining_character() {
var max_length = 100;
var character_entered = $('#text-content').val().length;
var character_remaining = max_length - character_entered;
$('#character-count').html(character_remaining);
if (max_length < character_entered) {
$('#character-count').css('color', '#FF0000');
} else {
$('#character-count').css('color', '#A0A0A0');
}
}
</script>
</body>
</html>