JSFiddle - React, Tailwind, and code Playground

HTML

<div id="uploaded"></div>

<input type="text" id="src" value="http://placekitten.com.s3.amazonaws.com/homepage-samples/408/287.jpg" />

CSS

#uploaded {
    height: 200px;
    width: 200px;
    border: 1px solid #aaa;

    background-size: 100%;
    background-repeat: no-repeat;
}

JavaScript

var src = document.getElementById("src");
src.onchange = function (ev) {
    document.getElementById('uploaded').style.backgroundImage = 'url(' + src.value +  ')';
};
src.onchange();