Validate File size before upload

Question

I need to validate the file which is to be uploaded to the server. The validation must be done before uploading it. i.e., validation completed at client side. This task shou

Answer 1

When it comes for a browser that supports HTML 5, it can be easily achieved with simple javascript:

Html Syntax

Javascript syntax

//gets the element by its id
var myFile = document.getElementById('myFile');

//binds to onchange event of the input field
myFile.addEventListener('change', function() {
  //this.files[0].size gets the size of your file.
  alert(this.files[0].size);

});

BUT, when it comes to an older browser (and we are all looking to you, Internet Explorer), the only way to do that on the client side is by using ActiveX:

var myFile = document.getElementById('myFile');

var myFSO = new ActiveXObject("Scripting.FileSystemObject");
var filepath = myfile.file.value;
var thefile = myFSO.getFile(filepath);
var size = thefile.size;
    alert(size + " bytes");