What is the difference between Font Awesome 4 and 5?

Question

Could you please write me : what is the difference between Font Awesome 4 and 5?

and what is the difference between :

<i class="fas fa-user" aria-hidden="true"></i>
<i class="fa fa-user" aria-hidden="true"></i>

Thank You !

Answer 1

Font Awesome 5 is a big refactoring of Font Awesome including new icons and breaking changes.

fas FontAwesome CSS class stands for font awesome solid (the Solid icon style) but fa is also kept for retro-compatibility. So, there is no difference between fas an fa that both applies the Solid icon style.

Regarding the differences between Font Awesome 4 and 5 :

• 5 icons styles (Solid, Brands, Regular, Light and Duotone) but only the first two are free (Solid and Brands)
• some icons have new names
• now all icons have an "outlined" style but this is in the Regular icon style which is not free. As a consequence, icons previously ending by -o does not exist anymore in FontAwesome version 5 Free.

Also have a look at the page Upgrade From Version 4 of Font Awesome docs for more info.