"Block download" function doesn't always work with PDFs

Steel Contributor

A few of our departments have been using the "block download" option for sharing confidential files. When they share Word, Excel or PowerPoint files, it works great. However, when they share PDFs, the viewers are sometimes able to download or print them. It seems that in many cases the recipient/viewer's browser is configured to open PDFs in a specific app (e.g.: Safari on Macs uses Preview; Chrome has its own integrated PDF viewer), and those apps don't respect the "block download" function. 

 

The only time I've seen it work properly is when the recipient/viewer is using MS Edge. 

 

Does anyone know if it's possible to make this work regardless of which browser the recipient is using? 

3 Replies
Best you can do here is to open a support ticket son Microsoft can be aware of this issue
Actually, it seems like whatever issue we were having in the past has been fixed. I hadn't tested this process since last Summer (~June 2021), but when sharing PDFs now with "block download" enabled, they appear to consistently open in the M365 PDF viewer in a browser, regardless of other PDF viewers installed/configured for that browser. The main offenders in the past have been Safari and Chrome, but they're not a problem any more (apparently).
Old post but I've just tested sharing a pdf file with my personal email in read-only and blocked download options. I'm loading the link in Edge which is set as my default pdf reader but after entering verification code I get an error message that file can't be downloaded. From what I know pdf files must be dowloaded to be opened in a browser. Maybe this only works for pdf files generated from Office apps as I know this is the case when applying sensitivity labels (purview).