For a few decades, PDF has become an extremely important file format. If you want to create documents that can be viewed under all major operating systems, PDF is the ticket, as it maintains the overall look and feel of documents regardless of what platform they are viewed under.

There are a few pdf reader available for Linux, but Okular stands out as the best of the bunch, due to its ability to comment on, highlight, and otherwise annotate PDFs. Because it can view a number of different document formats, including PDFs, EPUB ebooks, CBR and CBZ comic books, DjVu, images, and more, besides, it annotate and mark up PDF files with comments, highlights, shapes, stamps, and more, it also can extract text from a PDF to a text file, Set bookmarks for later viewing as well as trim white page borders.

But if you do not think Okular is the best pdf viewer for Linux, there are other pdf viewer for Linux you can use.

Evince is the default PDF viewer in most GNOME-based Linux distributions, so if you don't want to install all those KDE dependencies, Evince is probably your next choice. It's lightweight, simple, and easy to use, though it doesn't have too many advanced features. You can rotate PDFs, add bookmarks, and change the sidebar's view mode, but other than that, you don't have much. If all you're doing is reading the occasional PDF, it's great, but you won't find any annotation features here.

Adobe Reader, it is well know to people that adobe reader is a good pdf reader software, also, it has a Linux version available, it's still the standard, which means if you ever have compatibility issues in something like Okular or Evince, Adobe Reader will probably handle it just fine. You don't need to install it now, just know that if you ever have problems, it's worth keeping in mind.

Lastly, it's worth noting that lots of Windows PDF apps work great under WINE, including PDF X-Change, Foxit, and Sumatra. So, while they won't look fantastic under Linux, they're great if you need some more advanced reading and editing tools, since most Linux apps are a bit lacking.
These aren't the only PDF viewers for Linux, but they are, in our opinion, the best.

If you are a designer and want to view pdf on windows system but do not have a pdf viewer, then you can convert pdf to dxf with the help of free pdf to dxf converter. Or you can also convert pdf to dwg with the pdf to dwg converter, after converting, you can view dwg or dxf files using the autocad software.