maxcdn.bootstrapcdn.com/font-awesome/4.2.0/css/font-awesome.min.css code example

Example 1: font awesome cdn

<link rel="stylesheet" href="https://pro.fontawesome.com/releases/v5.10.0/css/all.css" integrity="sha384-AYmEC3Yw5cVb3ZcuHtOA93w35dYTsvhLPVnYs9eStHfGJvOvKxVfELGroGkvsg+p" crossorigin="anonymous"/>

Example 2: font awesome cdn

<!-- HTML FontAwesome CDN Link -->
<link href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">