JSFiddle - React, Tailwind, and code Playground

HTML

<div id="a" style="transition-property: -webkit-transform; -webkit-transform-origin: 0px 0px 0px; -webkit-transform: translate(0px, -13361.5px) scale(1) translateZ(50px);">
    Test
</div>

JavaScript

a = document.getElementById('a');
function getTranslateZ(obj)
{
    var style = obj.style,
        transform = style.transform || style.webkitTransform || style.mozTransform,
        zT = transform.match(/translateZ\(([0-9]+(px|em|%|ex|ch|rem|vh|vw|vmin|vmax|mm|cm|in|pt|pc))\)/);
    return zT ? zT[1] : '0';
}
function getComputedTranslateZ(obj)
{
    if(!window.getComputedStyle) return;
    var style = getComputedStyle(obj),
        transform = style.transform || style.webkitTransform || style.mozTransform;
    var mat = transform.match(/^matrix3d\((.+)\)$/);
    return mat ? ~~(mat[1].split(', ')[14]) : 0;
}
console.log(getTranslateZ(a), getComputedTranslateZ(a))