Linux has quite a few PDF readers available, but Okular stands out as the best of the bunch, due to its ability to comment on, highlight, and otherwise annotate PDFs.
- View a number of different document formats, including PDFs, ePub ebooks, CBR and CBZ comic books, DjVu, images and more.
- Annotate and mark up PDF files with comments, highlights, shapes, stamps and more.
- Extract text from a PDF to a text file.
- Set bookmarks for later viewing.
- Trim white page borders.
Okular may not be as feature-filled as some of the PDF editors and viewers on Windows, but it's by far the most feature-filled on Linux. It's the only app that can annotate PDFs and it has several other usability options in its preferences so you can tweak the program to fit your workflow (whether that's speeding it up by changing its memory usage, changing the view mode or tweaking the program's overall appearance). It's also a pretty snappy program, even on slower machines with large PDFs, so coupled with its memory tweaking preferences, you should have no problem opening PDFs quickly and getting to the good stuff.
Okular is a KDE program. This means GNOME users will have to download lots of dependencies to run it, which will take up a good amount of space (not to mention it'll look a bit out of pace with their other programs). Also, while it's the most feature-filled reader on Linux, it can't edit PDFs — in fact, most readers can't. If you want to full-on edit PDFs, you'll have to use something like LibreOffice or a dedicated editor like PDFedit instead.
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 has a Linux version available and as always, we don't recommend it as your go-to reader. That said, 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, as 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've got a favourite we didn't mention, let us know about it in the comments.
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