font awesome 3 cdn code example
Example 1: font awesome 4.7 cdn
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" integrity="sha256-eZrrJcwDc/3uDhsdt61sL2oOBY362qM3lon1gyExkL0=" crossorigin="anonymous" />
Example 2: fontawesome cdn
<link rel="stylesheet" href="path/to/font-awesome/css/font-awesome.min.css">