(function () { document .getElementById("imageUpload") .addEventListener("change", readURL, true); function readURL() { const file = document.getElementById("imageUpload").files[0]; const reader = new FileReader(); reader.onloadend = function () { document.getElementById("image").style.backgroundImage = "url(" + reader.result + ")"; }; if (file) { reader.readAsDataURL(file); } else { } } })();