jQuery File Upload is a blueimp widget with multiple file selection, drag&drop support, progress bars and preview images for jQuery.
It supports cross-domain, chunked and resumable file uploads and client-side image resizing.
It works with any server-side platform (PHP, Python, Ruby on Rails, Java, Node.js, Go etc.) that supports standard HTML form file uploads.

Features

• Multiple file upload:
  Allows to select multiple files at once and upload them simultaneously.

• Drag & Drop support:
  Allows to upload files by dragging them from your desktop or filemanager and dropping them on your browser window.

• Upload progress bar:
  Shows a progress bar indicating the upload progress for individual files and for all uploads combined.

• Cancelable uploads:
  Individual file uploads can be canceled to stop the upload progress.

• Resumable uploads:
  Aborted uploads can be resumed with browsers supporting the Blob API.

• Chunked uploads:
  Large files can be uploaded in smaller chunks with browsers supporting the Blob API.

• Client-side image resizing:
  Images can be automatically resized on client-side with browsers supporting the required JS APIs.

• Preview images, audio and video:
  A preview of image, audio and video files can be displayed before uploading with browsers supporting the required APIs.

• No browser plugins (e.g. Adobe Flash) required:
  The implementation is based on open standards like HTML5 and JavaScript and requires no additional browser plugins.

• Graceful fallback for legacy browsers:
  Uploads files via XMLHttpRequests if supported and uses iframes as fallback for legacy browsers.

• HTML file upload form fallback:
  Allows progressive enhancement by using a standard HTML file upload form as widget element.

• Cross-site file uploads:
  Supports uploading files to a different domain with cross-site XMLHttpRequests or iframe redirects.

• Multiple plugin instances:
  Allows to use multiple plugin instances on the same webpage.

• Customizable and extensible:
  Provides an API to set individual options and define callBack methods for various upload events.

• Multipart and file contents stream uploads:
  Files can be uploaded as standard "multipart/form-data" or file contents stream (HTTP PUT file upload).

• Compatible with any server-side application platform:
  Works with any server-side platform (PHP, Python, Ruby on Rails, Java, Node.js, Go etc.) that supports standard HTML form file uploads.

Useful links

• Official demo
• The list of options provided