When you’re clicking a PDF file on one of your SharePoint sites, the file can only be saved and not opened directly.
This is by default a SharePoint security setting to prevent scripting or PDF attacks. The setting can be found in the Browser File Handling section which is set to Strict as default. If you do not have a problem with possible security risks, you can change the default behavior by following the steps below.
1. Open your SharePoint Central Administration site (http://servername:adminport/default.aspx) 2. Click on Manage web applications > Your SharePoint site name > Menu General settings > General settings > Section Browser File Handling
3. Change the setting Strict to Permissive and click OK
That’s it. PDF files can now be opened directly from your SharePoint site.