W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<body onload="myFunction()">

<p id="demo"></p>
  
<script>
function myFunction(){
  var x = document.getElementById("myFile");
  var txt = "";
  if ('files' in x) {
    if (x.files.length == 0) {
      txt = "Select one or more files.";
    } else {
      for (var i = 0; i < x.files.length; i++) {
        txt += "<br><strong>" + (i+1) + ". file</strong><br>";
        var file = x.files[i];
        if ('name' in file) {
          txt += "name: " + file.name + "<br>";
        }
        if ('size' in file) {
          txt += "size: " + file.size + " bytes <br>";
        }
      }
    }
  } 
  else {
    if (x.value == "") {
      txt += "Select one or more files.";
    } else {
      txt += "The files property is not supported by your browser!";
      txt  += "<br>The path of the selected file: " + x.value; // If the browser does not support the files property, it will return the path of the selected file instead. 
    }
  }
  document.getElementById("demo").innerHTML = txt;
}
</script>

<p><strong>Tip:</strong> Use the Control or the Shift key to select multiple files.</p>

</body>
</html>

​x
 
<!DOCTYPE html><html><body onload="myFunction()">​<input type="file" id="myFile" multiple size="50" onchange="myFunction()">​<p id="demo"></p>  <script>function myFunction(){  var x = document.getElementById("myFile");  var txt = "";  if ('files' in x) {    if (x.files.length == 0) {      txt = "Select one or more files.";    } else {      for (var i = 0; i < x.files.length; i++) {        txt += "<br><strong>" + (i+1) + ". file</strong><br>";        var file = x.files[i];        if ('name' in file) {          txt += "name: " + file.name + "<br>";        }        if ('size' in file) {          txt += "size: " + file.size + " bytes <br>";        }      }    }  }   else {    if (x.value == "") {      txt += "Select one or more files.";    } else {      txt += "The files property is not supported by your browser!";      txt  += "<br>The path of the selected file: " + x.value; // If the browser does not support the files property, it will return the path of the selected file instead.     }  }  document.getElementById("demo").innerHTML = txt;}</script>​<p><strong>Tip:</strong> Use the Control or the Shift key to select multiple files.</p>​</body></html>​