jQuery animate function equivalent in pure JavaScript

You can acheive complex animations with pure javascript by using setTimeout and setInterval methods.

Please check here.

Here is the key part of moving an element:

function move(elem) {
    var left = 0
    function frame() {
        left++  // update parameters
        elem.style.left = left + 'px' // show frame
        if (left == 100)  // check finish condition
            clearInterval(id)
    }
    var id = setInterval(frame, 10) // draw every 10ms
}

This version uses vanilla javascript .animate() function, which is better or more performant
than requestAnimation frame. & it is also the proper alternative to JQuerys .animate().
you can play around with the iterations, timing functions & fill method aswell as daisy chain it with other animations

document.getElementById("Elem");
         Elem.style.position = "absolute";
         Elem.animate({
              top: ['8px', '280px']
                 },{ duration: 1760,        // number in ms [this would be equiv of your speed].
                     easing: 'ease-in-out',
                     iterations: 1,         // infinity or a number.
                  // fill: ''
        });   

I believe the setTimeout & setInterval functions both use the unsafe eval() function under the hood, but not 100% sure about that, just remember reading an article about it...
Don't Quote me on that! just research it,
but the code I wrote out has been tested to be working.. hope this helps someone...