On your Sitecore site what is the media file extension you see? If you see .ashx for all your media (images, pdfs) read on. Ideally the IIS application pool for your website should be configured to use Integrated mode instead of classic mode. If that is the case, there is one default Sitecore 8 setting that you should change in your Sitecore.config FROM: <setting name="Media.RequestExtension" value="ashx"/> TO: <setting name="Media.RequestExtension" value=""/> This configures Sitecore to use the original file extensions rather than .ashx extension. So images would be jpg, gif, png's while pdfs would have the pdf extension. I also notice that Sitecore themselves have this configured on their website, so we should be good making this change. There are multiple benefits to the end user. They know the file types of media like pdfs before clicking on the download link CDN have cache settings that will be honoured