Try it Editor: The tab-size Property

Edit This Code :

<!DOCTYPE html>
<html>
<head>
<style> 
#t1 {
    -moz-tab-size: 4; /* Firefox */
    -o-tab-size: 4; /* Opera 10.6-12.1 */
    tab-size: 4;
}

#t2 {
    -moz-tab-size: 16; /* Firefox */
    -o-tab-size: 16; /* Opera 10.6-12.1 */
    tab-size: 16;
}
</style>
</head>
<body>
<h1>The tab-size Property</h1>

<pre id="t1">
I use tab-size 4
</pre>

<pre id="t2">
I use tab-size 16
</pre>

<p><strong>Note:</strong> The tab-size property is currently supported in Chrome, Safari and Opera.</p>

<p><strong>Note:</strong> Firefox supports an alternative, the -moz-tab-size property. Opera 10.6 to 12.1 
also supports an alternative, the -o-tab-size property.</p>

</body>
</html>
Result :