Documentation for SharePoint Bulk File Upload Web Part. SharePoint Uploader
SSharePoint Upload Web Part is a Silverlight web part for easy & simple uploading of multiple documents to SharePoint 2016, 2013, 2010, or 2007 document library. SharePoint Bulk File Upload allows SharePoint users to upload multiple files into the document library in a quick and convenient way, monitor the upload process, and view the files you are working with. You can also try HTML5 SharePoint File Upload Web Part for better user experience in SharePoint 2013.