.parent {
width:100%;
}
.child {
display:inline-block;
}<div class="parent">
<div class="child">child1</div>
<div class="child">child2</div>
<div class="child">child3</div>
</div><input type='file' accept='image/*' onchange='openFile(event)'><br>
<img id='output'>var openFile = function(event) {
var input = event.target;
var reader = new FileReader();
reader.onload = function(){
var dataURL = reader.result;
var output = document.getElementById('output');
output.src = dataURL;
};
reader.readAsDataURL(input.files[0]);
};