Tôi biết câu hỏi này liên quan đến FireFox, nhưng bạn cũng có thể có tính năng này trong Chrome (Firefox sẽ không cho phép bạn chèn JS làm dấu trang):

Thêm mã javascript này dưới dạng url đánh dấu:
javascript:void function(b,p)%7Bfunction l(k,c,b,e,g,d,f)%7Breturn"<div style%3D%27position:absolute%3B-webkit-transform-origin: 0 0 0%3B"%2B("background:"%2Bf%2B"%3B")%2B("width:"%2Be%2B"px%3B height:"%2Bg%2B"px%3B")%2B("-webkit-transform:"%2B("translate3d("%2Bk%2B"px,"%2Bc%2B"px,"%2Bb%2B"px)")%2B("rotateX(270deg) rotateY("%2Bd%2B"deg)")%2B"%3B")%2B"%27></div>"%7Dfunction o(k,c,d,f)%7Bfor(var j%3Dk.childNodes,n%3Dj.length,m%3D0%3Bm<n%3Bm%2B%2B)%7Bvar a%3Dj%5Bm%5D%3Bif(1%3D%3D%3Da.nodeType)%7Ba.style.overflow%3D"visible"%3Ba.style.WebkitTransformStyle%3D"preserve-3d"%3Ba.style.WebkitTransform%3D"translateZ("%2B(b%2B(n-m)*q).toFixed(3)%2B"px)"%3Bvar h%3Dd,i%3Df%3Ba.offsetParent%3D%3D%3Dk%26%26(h%2B%3Dk.offsetLeft,i%2B%3Dk.offsetTop)%3Bo(a,c%2B1,h,i)%3Be%2B%3Dl(h%2Ba.offsetLeft,i%2Ba.offsetTop,(c%2B1)*b,a.offsetWidth,b,0,g%5Bc%25(g.length-1)%5D)%3Be%2B%3Dl(h%2Ba.offsetLeft%2Ba.offsetWidth,i%2Ba.offsetTop,(c%2B1)*b,a.offsetHeight,b,270,g%5Bc%25(g.length-1)%5D)%3Be%2B%3Dl(h%2Ba.offsetLeft,i%2Ba.offsetTop%2Ba.offsetHeight,(c%2B1)*b,a.offsetWidth,b,0,g%5Bc%25(g.length-1)%5D)%3Be%2B%3Dl(h%2Ba.offsetLeft,i%2Ba.offsetTop,(c%2B1)*b,a.offsetHeight,b,270,g%5Bc%25(g.length-1)%5D)%7D%7D%7Dvar g%3D"%23C33,%23ea4c88,%23663399,%230066cc,%23669900,%23ffcc33,%23ff9900,%23996633".split(","),q%3D0.001,e%3D"",d%3Ddocument.body%3Bd.style.overflow%3D"visible"%3Bd.style.WebkitTransformStyle%3D"preserve-3d"%3Bd.style.WebkitPerspective%3Dp%3Bvar r%3D(window.innerWidth/2).toFixed(2),s%3D(window.innerHeight/2).toFixed(2)%3Bd.style.WebkitPerspectiveOrigin%3Dd.style.WebkitTransformOrigin%3Dr%2B"px "%2Bs%2B"px"%3Bo(d,0,0,0)%3Bvar f%3Ddocument.createElement("DIV")%3Bf.style.display%3D"none"%3Bf.style.position%3D"absolute"%3Bf.style.top%3D0%3Bf.innerHTML%3De%3Bd.appendChild(f)%3Bvar j%3D"NO_FACES"%3Bdocument.addEventListener("mousemove",function(b)%7Bif("DISABLED"!%3D%3Dj)%7Bvar c%3Db.screenX/screen.width,b%3D(360*(1-b.screenY/screen.height)-180).toFixed(2),c%3D(360*c-180).toFixed(2)%3Bd.style.WebkitTransform%3D"rotateX("%2Bb%2B"deg) rotateY("%2Bc%2B"deg)"%7D%7D,!0)%3Bdocument.addEventListener("mouseup",function()%7Bswitch(j)%7Bcase "NO_FACES":j%3D"FACES"%3Bf.style.display%3D""%3Bbreak%3Bcase "FACES":j%3D"NO_FACES",f.style.display%3D"none"%7D%7D,!0)%7D(25,5E3)%3B

Sau khi thêm vào nhấp vào dấu trang trên bất kỳ trang web. Bạn có thể nhấp để hiển thị đường viền và kéo để xem như trong Firefox.