I know this question is in regards to FireFox, but you can get this feature in Chrome as well (Firefox won't let you insert JS as a bookmark):
Add this javascript code as a bookmark url:
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
Once added click the bookmark on any website. You can click to show outlines and drag to view like in Firefox.
7Can you please reconsider to change your accepted answer? Firefox 47 changed this and that 3D functionality completely removed now – rubo77 – 2016-07-04T09:16:53.580