Get file size before uploading


Is there any way to find out the file size before uploading the file using AJAX / PHP in change event of input file?

For the HTML bellow

<input type="file" id="myFile" />

try the following:

//binds to onchange event of your input field
$('#myFile').bind('change', function() {

  //this.files[0].size gets the size of your file.
  alert(this.files[0].size);

});

See following thread:

How to check file input size with jQuery?


<script type="text/javascript">
function AlertFilesize(){
    if(window.ActiveXObject){
        var fso = new ActiveXObject("Scripting.FileSystemObject");
        var filepath = document.getElementById('fileInput').value;
        var thefile = fso.getFile(filepath);
        var sizeinbytes = thefile.size;
    }else{
        var sizeinbytes = document.getElementById('fileInput').files[0].size;
    }

    var fSExt = new Array('Bytes', 'KB', 'MB', 'GB');
    fSize = sizeinbytes; i=0;while(fSize>900){fSize/=1024;i++;}

    alert((Math.round(fSize*100)/100)+' '+fSExt[i]);
}
</script>

<input id="fileInput" type="file" onchange="AlertFilesize();" />

Work on IE and FF


Here's a simple example of getting the size of a file before uploading. It's using jQuery to detect whenever the contents are added or changed, but you can still get files[0].size without using jQuery.

$(document).ready(function() {
  $('#openFile').on('change', function(evt) {
    console.log(this.files[0].size);
  });
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form action="upload.php" enctype="multipart/form-data" method="POST" id="uploadform">
  <input id="openFile" name="img" type="file" />
</form>

Here's a more complete example, some proof of concept code to Drag and Drop files into FormData and upload via POST to a server. It includes a simple check for file size.


I had the same problem and seems like we haven't had an accurate solution. Hope this can help other people.

After take time exploring around, I finally found the answer. This is my code to get file attach with jQuery:

var attach_id = "id_of_attachment_file";
var size = $('#'+attach_id)[0].files[0].size;
alert(size);

This is just the example code for getting the file size. If you want do other stuffs, feel free to change the code to satisfy your needs.


Best solution working on all browsers ;)

function GetFileSize(fileid) {
    try {
        var fileSize = 0;
        // for IE
        if(checkIE()) { //we could use this $.browser.msie but since it's deprecated, we'll use this function
            // before making an object of ActiveXObject, 
            // please make sure ActiveX is enabled in your IE browser
            var objFSO = new ActiveXObject("Scripting.FileSystemObject");
            var filePath = $("#" + fileid)[0].value;
            var objFile = objFSO.getFile(filePath);
            var fileSize = objFile.size; //size in b
            fileSize = fileSize / 1048576; //size in mb 
        }
        // for FF, Safari, Opeara and Others
        else {
            fileSize = $("#" + fileid)[0].files[0].size //size in b
            fileSize = fileSize / 1048576; //size in mb 
        }
        alert("Uploaded File Size is" + fileSize + "MB");
    }
    catch (e) {
        alert("Error is :" + e);
    }
}

from http://www.dotnet-tricks.com/Tutorial/jquery/HHLN180712-Get-file-size-before-upload-using-jquery.html

UPDATE : We'll use this function to check if it's IE browser or not

function checkIE() {
    var ua = window.navigator.userAgent;
    var msie = ua.indexOf("MSIE ");

    if (msie > 0 || !!navigator.userAgent.match(/Trident.*rv\:11\./)){  
        // If Internet Explorer, return version number
        alert(parseInt(ua.substring(msie + 5, ua.indexOf(".", msie))));
    } else {
        // If another browser, return 0
        alert('otherbrowser');
    }

    return false;
}

$(document).ready(function() {
  $('#openFile').on('change', function(evt) {
    console.log(this.files[0].size);
  });
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form action="upload.php" enctype="multipart/form-data" method="POST" id="uploadform">
  <input id="openFile" name="img" type="file" />
</form>


Browsers with HTML5 support has files property for input type. This will of course not work in older IE versions.

var inpFiles = document.getElementById('#fileID');
for (var i = 0; i < inpFiles.files.length; ++i) {
    var size = inpFiles.files.item(i).size;
    alert("File Size : " + size);
}

ucefkh's solution worked best, but because $.browser was deprecated in jQuery 1.91, had to change to use navigator.userAgent:

function IsFileSizeOk(fileid) {
    try {
        var fileSize = 0;
        //for IE
        if (navigator.userAgent.match(/msie/i)) {
            //before making an object of ActiveXObject, 
            //please make sure ActiveX is enabled in your IE browser
            var objFSO = new ActiveXObject("Scripting.FileSystemObject");
            var filePath = $("#" + fileid)[0].value;
            var objFile = objFSO.getFile(filePath);
            var fileSize = objFile.size; //size in b
            fileSize = fileSize / 1048576; //size in mb 
        }
        //for FF, Safari, Opeara and Others
        else {
            fileSize = $("#" + fileid)[0].files[0].size //size in b
            fileSize = fileSize / 1048576; //size in mb 
        }
        return (fileSize < 2.0);
    }
    catch (e) {
        alert("Error is :" + e);
    }
}

you need to do an ajax HEAD request to get the filesize. with jquery it's something like this

  var req = $.ajax({
    type: "HEAD",
    url: yoururl,
    success: function () {
      alert("Size is " + request.getResponseHeader("Content-Length"));
    }
  });

Please do not use ActiveX as chances are that it will display a scary warning message in Internet Explorer and scare your users away.

ActiveX warning

If anyone wants to implement this check, they should only rely on the FileList object available in modern browsers and rely on server side checks only for older browsers (progressive enhancement).

function getFileSize(fileInputElement){
    if (!fileInputElement.value ||
        typeof fileInputElement.files === 'undefined' ||
        typeof fileInputElement.files[0] === 'undefined' ||
        typeof fileInputElement.files[0].size !== 'number'
    ) {
        // File size is undefined.
        return undefined;
    }

    return fileInputElement.files[0].size;
}

You can use PHP filesize function. During upload using ajax, please check the filesize first by making a request an ajax request to php script that checks the filesize and return the value.


You can by using HTML5 File API: http://www.html5rocks.com/en/tutorials/file/dndfiles/

However you should always have a fallback for PHP (or any other backend language you use) for older browsers.


Personally, I would say Web World's answer is the best today, given HTML standards. If you need to support IE < 10, you will need to use some form of ActiveX. I would avoid the recommendations that involve coding against Scripting.FileSystemObject, or instantiating ActiveX directly.

In this case, I have had success using 3rd party JS libraries such as plupload which can be configured to use HTML5 apis or Flash/Silverlight controls to backfill browsers that don't support those. Plupload has a client side API for checking file size that works in IE < 10.