jQuery File Upload: Setup and Secure PHP Handling

Last updated: August 25, 2026.

The blueimp jQuery File Upload widget provides multiple selection, drag and drop, progress events, chunking, and previews. It is a client-side component: your server endpoint remains responsible for authentication, validation, storage, and access control.

Basic form

<form id="fileupload" action="/upload.php" method="post"
      enctype="multipart/form-data">
  <input type="file" name="files[]" multiple>
  <button type="submit">Upload files</button>
</form>

Initialize the widget

Load jQuery, the jQuery UI widget dependency included by the project, and jquery.fileupload.js, then initialize the form:

$('#fileupload').fileupload({
  dataType: 'json',
  url: '/upload.php',
  sequentialUploads: true,
  maxFileSize: 5_000_000,
  acceptFileTypes: /\.(?:jpe?g|png)$/i
}).on('fileuploadprogressall', function (event, data) {
  const percent = Math.floor(data.loaded / data.total * 100);
  $('#upload-progress').text(percent + '%');
}).on('fileuploaddone', function (event, data) {
  console.log(data.result);
}).on('fileuploadfail', function () {
  console.error('Upload failed');
});

Client-side limits improve feedback but can be bypassed. Apply the same rules in upload.php; the secure PHP upload example shows MIME inspection, generated filenames, and protected storage.

Deployment checklist

• Do not deploy a demonstration upload handler as a public endpoint.
• Require authentication, authorization, and CSRF protection.
• Return JSON with stable success and error fields.
• Disable script execution in upload storage and preferably keep it outside the web root.
• Restrict cross-origin requests to explicitly trusted origins.
• Review the project’s security guidance before using optional preview or server components.

For installation files and API options, see the blueimp jQuery File Upload repository. For a new interface that needs only simple uploads and progress, native FormData, fetch(), or XMLHttpRequest may be sufficient without a jQuery dependency.