SharePoint Online: How to Restrict Download for Document library

For IRM protected document library, you will see this error while uploading protected or digitally signed PDF files. Something that working fine for Sharepoint 2010 but NOT for SharePoint Online.

According to Microsoft article:

IRM protection cannot be applied to protected documents as SharePoint needs to open the documents on upload

This is most demanded features for SharePoint Online UserVoice suggestion. 

Unfortunately, This UserVoice instance is no longer available anymore. While waiting for Microsoft to allow upload password protected / AIP protected / digitally signed PDF files in SharePoint IRM document library, workaround need to be in place.

Since we are not able to upload protected PDF into IRMed folder, only option is upload into non-IRM folder. 

To further protect the PDF, customer have asked on how to restrict download PDF from document library.

How to hide/restrict Download from the document library ?

Please follow the step below to remove Download option.

1. Navigate to Site Permission > Advanced Permission Settings.
2. Under Permission, select Create Group.
   
   
   
   
   
3. Under Give Group Permission to this Site, tick View Only and click Create.
   
   
   
   
   
4. Now you won't see Download option for the user assigned with View Only permission.

No Save/Download option in preview too.