How to optimize font resources through asynchronous loading to avoid the "font blocking" phenomenon?

When a web page loads font resources, asynchronous loading can effectively avoid "font blocking" phenomena (such as FOIT/FOUT) caused by uncompleted font file loading, improving page rendering speed and user experience. The core methods to achieve asynchronous loading include: - **Using preload for preloading**: Load fonts in advance via `<link rel="preload" href="font.woff2" as="font" type="font/woff2" crossorigin>`, which has higher priority than ordinary resources and reduces loading delay. - **Setting the font-display property**: Add `font-display: swap` (prioritize displaying system fonts and replace after loading is complete) or `fallback` (display system fonts after a short period of invisibility) in the @font-face rule to avoid long-term invisible text. - **JavaScript dynamic loading**: Create a link tag through JS and insert it into the DOM to achieve asynchronous loading of font resources, which can be combined with load event monitoring to ensure styles are applied after the font is loaded. It is recommended to prioritize the preload + font-display combination scheme and compress font files (such as using WOFF2 format) to shorten loading time. Testing performance in different browsers can further optimize the web font loading experience.