You can preload custom fonts using
<link rel="preload" as="font" href="zombie-fonty.woff2">Code language: HTML, XML (xml)in your head. This allows the browser to schedule the download of the font even before it finds the font in the CSS @font-face rule. It’s kind of like letting the quartermaster know about a particular need or requirement before he finds where it’s listed. He can send an assistant to get it at the beginning instead of waiting till he’s waded through a mountain of paperwork.