how can i view pdf file with out downloading them on safari

You can set this up in your browser. Instructions are in Acrobat Preferences > Internet with a link that takes you here:

https://helpx.adobe.com/acrobat/using/display-pdf-in-browser.html

Scroll down a bit to see how to go to Safari Preferences and select Reader or Acrobat as a plug-in.

You should not have to download a PDF just to view it.

I think what you mean is when you click on a link in Safari the PDF opens in Safari instead of downloading as a PDF?

If so, right mouse click on the link and select 'download file as' and save it where ever you want.

Hope that helps.

Do you have Acrobat DC or Acrobat Reader?  Either way you will need to download the file to view it.   That's how PDFs work.

Nancy