Responsive font size using CSS/jQuery

Question

I want to create a responsive text inside a div.

I tried jquery-textfill and FlowType, but they are not working for me at all.

FlowType does

Answer 1

CSS

.internal{width:100%;height:100%}
.external{width:auto;height:auto;background-color:yellow}

JQuery

$(".external").fitText(0.5);

DEMO 1

Update 1:

CSS

.internal{width:auto;height:auto;position:absolute;}
.external{width:400px;height:50px;background-color:yellow;position:relative;}

JQuery

$(".external").fitText();

DEMO 2

Update 2:

JQuery

var ex=$(".external");
var h=ex.height();
var w=ex.width();
ex.fitText(Math.min(h,w)/Math.max(h,w) );

DEMO 3

Update 4:

Bigtext is a jQuery text plugin that automatically enlarge the font size of your text to fill its parent container, without overflowing the container Div. jQuery Bigtext Plugin