Full preload a html5 video

videoFullPreload.bookmarklet.js

javascript:void(Array.prototype.slice.call(document.getElementsByTagName('video')).map(function(a){return!(a.src&&a.src.match('blob'))&&fetch(a.currentSrc||a.src).then(function(b){return b.blob()}).then(function(b){return a.src=URL.createObjectURL(b)})}))

videoFullPreload.js

const makePreload = video => !(video.src && video.src.match('blob')) && fetch(video.currentSrc || video.src).then(response => response.blob()).then(blob => video.src = URL.createObjectURL(blob));
//[...document.getElementsByTagName('video')].map(makePreload);