Preload resource inside the browser
1.static tag <link rel="preload" as="..."> Just load some resource, not be run. <link rel-"preload" href="/pre/res/stylepre.css" as="style"> 2. dynamic adding into head by script <script> const prelink = document.createElement('link'); prelink.rel="preload"; prelink.as="style"; prelink.href="/pre/res/stylepre.css"; document.head.appendChild(prelink); </script> 3. check const bPreload = ()=>{ const pre=document.createElement('link'); const plist=pre.relList; if(!plist || !plist.supports){ return false;} return plist.supports('preload'); } 4.onload 4.1 call back function <link rel-"preload" href="..." as="..." onload="preloadDone()"> 4.2 running all right <link rel-"preload" href="/pre/res/stylepre.css" as="style" onload="this.rel=stylesheet"...