[v1.2.3] Free Download Font Awesome Manager
XenForo uses the icon font Font Awesome Pro 5 that contains over 7.000 icons of which XenForo typically uses only a few hundred.
But as all icons are included in the CSS and font files, browsers have to download the full font files and CSS which does cause a significant overhead in most cases.
By subsetting the font to include only those icons that are actually being used, the size of the font files and CSS can often be drastically reduced which does improve page loading time.
Typically, the size of the font files can be reduced by over 80%