font-awesome 4.4 icons code example
Example 1: fontawesome 4.7 icon
<i class="fa fa-facebook" aria-hidden="true"></i>
Example 2: fa icons
<script src='https://kit.fontawesome.com/a076d05399.js'></script>
<i class="fa fa-facebook" aria-hidden="true"></i>
<script src='https://kit.fontawesome.com/a076d05399.js'></script>