How can I upload files asynchronously with jQuery?

Question

I would like to upload a file asynchronously with jQuery.

$(document).ready(function () {
    $("#uploadbutton").click(function () {
        var filename = $("#file").val();

        $.ajax({
            type: "POST",
            url: "addFile.do",
            enctype: 'multipart/form-data',
            data: {
                file: filename
            },
            success: function () {
                alert("Data Uploaded: ");
            }
        });
    });
});


File

Instead of the file being uploaded, I am only getting the filename. What can I do to fix this problem?

user_12870 · Answer

2019 Update: It still depends on the browsers your demographic uses.

An important thing to understand with the "new" HTML5 file API is that it wasn't supported until IE 10. If the specific market you're aiming at has a higher-than-average propensity toward older versions of Windows, you might not have access to it.

As of 2017, about 5% of browsers are one of IE 6, 7, 8 or 9. If you head into a big corporation (e.g., this is a B2B tool or something you're delivering for training) that number can skyrocket. In 2016, I dealt with a company using IE8 on over 60% of their machines.

It's 2019 as of this edit, almost 11 years after my initial answer. IE9 and lower are globally around the 1% mark but there are still clusters of higher usage.

The important take-away from this —whatever the feature— is, check what browser your users use. If you don't, you'll learn a quick and painful lesson in why "works for me" isn't good enough in a deliverable to a client. caniuse is a useful tool but note where they get their demographics from. They may not align with yours. This is never truer than enterprise environments.

My answer from 2008 follows.

However, there are viable non-JS methods of file uploads. You can create an iframe on the page (that you hide with CSS) and then target your form to post to that iframe. The main page doesn't need to move.

It's a "real" post so it's not wholly interactive. If you need status you need something server-side to process that. This varies massively depending on your server. ASP.NET has nicer mechanisms. PHP plain fails, but you can use Perl or Apache modifications to get around it.

If you need multiple file uploads, it's best to do each file one at a time (to overcome maximum file upload limits). Post the first form to the iframe, monitor its progress using the above and when it has finished, post the second form to the iframe, and so on.

Or use a Java/Flash solution. They're a lot more flexible in what they can do with their posts...

Admin · Answer

I recommend using the Fine Uploader plugin for this purpose. Your JavaScript code would be:

$(document).ready(function() {
  $("#uploadbutton").jsupload({
    action: "addFile.do",
    onComplete: function(response){
      alert( "server response: " + response);
    }
  });
});

Mattias_261 · Answer

Note: This answer is outdated, it is now possible to upload files using XHR.

You cannot upload files using XMLHttpRequest (Ajax). You can simulate the effect using an iframe or Flash. The excellent jQuery Form Plugin that posts your files through an iframe to get the effect.

Darryl_Hein_5441 · Answer

A solution I found was to have the

user_1432509 · Answer

A modern approach without Jquery is to use the FileList object you get back from when user selects a file(s) and then use Fetch to post the FileList wrapped around a FormData object.

// The input DOM element // 
const inputElement = document.querySelector('input[type=file]');

// Listen for a file submit from user
inputElement.addEventListener('change', () => {
    const data = new FormData();
    data.append('file', inputElement.files[0]);
    data.append('imageName', 'flower');

    // You can then post it to your server.
    // Fetch can accept an object of type FormData on its  body
    fetch('/uploadImage', {
        method: 'POST',
        body: data
    });
});

user_5906922 · Answer

Sample: If you use jQuery, you can do easy to an upload file. This is a small and strong jQuery plugin, http://jquery.malsup.com/form/.

Example

var $bar   = $('.ProgressBar');
$('.Form').ajaxForm({
  dataType: 'json',

  beforeSend: function(xhr) {
    var percentVal = '0%';
    $bar.width(percentVal);
  },

  uploadProgress: function(event, position, total, percentComplete) {
    var percentVal = percentComplete + '%';
    $bar.width(percentVal)
  },

  success: function(response) {
    // Response
  }
});

I hope it would be helpful

user_6212857 · Answer

You can pass additional parameters along with file name on making asynchronous upload using XMLHttpRequest (without flash and iframe dependency). Append the additional parameter value with FormData and send the upload request.

var formData = new FormData();
formData.append('parameter1', 'value1');
formData.append('parameter2', 'value2'); 
formData.append('file', $('input[type=file]')[0].files[0]);

$.ajax({
    url: 'post back url',
    data: formData,
// other attributes of AJAX
});

Also, Syncfusion JavaScript UI file upload provides solution for this scenario simply using event argument. you can find documentation here and further details about this control here enter link description here

user_5349542 · Answer

You can use newer Fetch API by JavaScript. Like this:

function uploadButtonCLicked(){
    var input = document.querySelector('input[type="file"]')

    fetch('/url', {
      method: 'POST',
      body: input.files[0]
    }).then(res => res.json())   // you can do something with response
      .catch(error => console.error('Error:', error))
      .then(response => console.log('Success:', response));
}

Advantage: Fetch API is natively supported by all modern browsers, so you don't have to import anything. Also, note that fetch() returns a Promise which is then handled by using .then(..code to handle response..) asynchronously.

user_9059939 · Answer

For PHP, look for https://developer.hyvor.com/php/image-upload-ajax-php-mysql

HTML



    Image Upload with AJAX, PHP and MYSQL



    
    

Uploading...

JAVASCRIPT

var previewImage = document.getElementById("preview"),  
    uploadingText = document.getElementById("uploading-text");

function submitForm(event) {
    // prevent default form submission
    event.preventDefault();
    uploadImage();
}

function uploadImage() {
    var imageSelecter = document.getElementById("image-selecter"),
        file = imageSelecter.files[0];
    if (!file) 
        return alert("Please select a file");
    // clear the previous image
    previewImage.removeAttribute("src");
    // show uploading text
    uploadingText.style.display = "block";
    // create form data and append the file
    var formData = new FormData();
    formData.append("image", file);
    // do the ajax part
    var ajax = new XMLHttpRequest();
    ajax.onreadystatechange = function() {
        if (this.readyState === 4 && this.status === 200) {
            var json = JSON.parse(this.responseText);
            if (!json || json.status !== true) 
                return uploadError(json.error);

            showImage(json.url);
        }
    }
    ajax.open("POST", "upload.php", true);
    ajax.send(formData); // send the form data
}

PHP

 $maxFileSize)
        throw new Exception('Max size limit exceeded'); 
    // check if uploaded file is an image
    $imageData = getimagesize($image['tmp_name']);
    if (!$imageData) 
        throw new Exception('Invalid image');
    $mimeType = $imageData['mime'];
    // validate mime type
    $allowedMimeTypes = ['image/jpeg', 'image/png', 'image/gif'];
    if (!in_array($mimeType, $allowedMimeTypes)) 
        throw new Exception('Only JPEG, PNG and GIFs are allowed');

    // nice! it's a valid image
    // get file extension (ex: jpg, png) not (.jpg)
    $fileExtention = strtolower(pathinfo($image['name'] ,PATHINFO_EXTENSION));
    // create random name for your image
    $fileName = round(microtime(true)) . mt_rand() . '.' . $fileExtention; // anyfilename.jpg
    // Create the path starting from DOCUMENT ROOT of your website
    $path = '/examples/image-upload/images/' . $fileName;
    // file path in the computer - where to save it 
    $destination = $_SERVER['DOCUMENT_ROOT'] . $path;

    if (!move_uploaded_file($image['tmp_name'], $destination))
        throw new Exception('Error in moving the uploaded file');

    // create the url
    $protocol = stripos($_SERVER['SERVER_PROTOCOL'],'https') === true ? 'https://' : 'http://';
    $domain = $protocol . $_SERVER['SERVER_NAME'];
    $url = $domain . $path;
    $stmt = $mysqli -> prepare('INSERT INTO image_uploads (url) VALUES (?)');
    if (
        $stmt &&
        $stmt -> bind_param('s', $url) &&
        $stmt -> execute()
    ) {
        exit(
            json_encode(
                array(
                    'status' => true,
                    'url' => $url
                )
            )
        );
    } else 
        throw new Exception('Error in saving into the database');

} catch (Exception $e) {
    exit(json_encode(
        array (
            'status' => false,
            'error' => $e -> getMessage()
        )
    ));
}

user_10276599 · Answer

You can do the Asynchronous Multiple File uploads using JavaScript or jQuery and that to without using any plugin. You can also show the real time progress of file upload in the progress control. I have come across 2 nice links -

ASP.NET Web Forms based Mulitple File Upload Feature with Progress Bar
ASP.NET MVC based Multiple File Upload made in jQuery

The server side language is C# but you can do some modification for making it work with other language like PHP.

File Upload ASP.NET Core MVC:

In the View create file upload control in html:

Now create action method in your controller:

[HttpPost]
public async Task Add(IFormFile[] mediaUpload)
{
    //looping through all the files
    foreach (IFormFile file in mediaUpload)
    {
        //saving the files
        string path = Path.Combine(hostingEnvironment.WebRootPath, "some-folder-path"); 
        using (var stream = new FileStream(path, FileMode.Create))
        {
            await file.CopyToAsync(stream);
        }
    }
}

hostingEnvironment variable is of type IHostingEnvironment which can be injected to the controller using dependency injection, like:

private IHostingEnvironment hostingEnvironment;
public MediaController(IHostingEnvironment environment)
{
    hostingEnvironment = environment;
}

user_151666 · Answer

You could also consider using something like https://uppy.io.

It does file uploading without navigating away from the page and offers a few bonuses like drag & drop, resuming uploads in case of browser crashes/flaky networks, and importing from e.g. Instagram. It's open source and does not rely on jQuery/React/Angular/Vue, but can be used with it. Disclaimer: as its creator I'm biased ;)

user_860099 · Answer

Try

async function saveFile() 
{
    let formData = new FormData();           
    formData.append("file", file.files[0]);
    await fetch('addFile.do', {method: "POST", body: formData});    
    alert("Data Uploaded: ");
}

File

The content-type='multipart/form-data' is set by browser automatically, the file name is added automatically too to filename FormData parameter (and can be easy read by server). Here is more developed example with err handling and json adding

async function saveFile(inp) 
{
    let user = { name:'john', age:34 };
    let formData = new FormData();
    let photo = inp.files[0];      
         
    formData.append("photo", photo);
    formData.append("user", JSON.stringify(user));  
    
    try {
       let r = await fetch('/upload/image', {method: "POST", body: formData}); 
       console.log('HTTP response code:',r.status); 
       alert('success');
    } catch(e) {
       console.log('Huston we have problem...:', e);
    }
    
}





Before selecting the file Open chrome console > network tab to see the request details.



Because in this example we send request to https://stacksnippets.net/upload/image the response code will be 404 ofcourse...

user_6373505 · Answer

What if using promises which ajax and checking if the file is valid and well saved in your backend, so you can use some animation in front while user is navigating thought your page.

You can even make it paralel upload or stacking with recursive approach

user_10567845 · Answer

You can use the following code.

async: false(true)

How can I upload files asynchronously with jQuery?

34 Answers

2019 Update: It still depends on the browsers your demographic uses.

Example