In SharePoint 2013 the “Upload Multiple” Options has been depreciated.There are two alternative ways to Upload multiple documents though we will discuss both in this post.
Option 1 - Using the drag-and-drop functionality
Microsoft has done an incredible job by adding this feature to the highly popular document libraries. On any document library you can now simply Drag and Drop the document and it will be upload with a quick progress bar. Here is how this feature works
Simply select multiple document from local and drag it onto the document library.The window will change to “Drop here..”
You can see the Upload documents Status bar next at the Document Libraries title.
You would see Upload Complete once the upload completes.
Know Issues with Drag and Drop -
Feature will not work with the IE version Internet Explorer version 8.0.6001.18702IC
Option 2 - Windows Explorer view
Click Start, click Run, type services.msc, and then press Enter.
In the list of services, locate the WebClient service, and then make sure that its status in the Status column is set to Started. If its status is not set to Started, double-click WebClient, click Start, and then click OK.
Once done restart the browser and try opening the Windows Explorer again. In the Windows Explorer you can copy and paste Multiple documents as done in earlier SharePoint versions.