Okular
Okular is a free, open-source PDF tool for Windows and Linux. Okular can view and annotate documents of various formats, including PDF, Postscript, Comic Book, and various image formats. It has 1,553 GitHub stars and is released under the GPL-2.0-or-later license, and people use it instead of Adobe Acrobat Reader.
github.com/KDE/okular (opens in a new tab)
Data as of from the GitHub API; description from the project's repository. Report an error
- Official
- Linux
- Windows
- PDF editors & tools
- Maintained
About Okular
Okular can view and annotate documents of various formats, including PDF, Postscript, Comic Book, and various image formats. It supports native PDF annotations.
Replaces
Commercial software people commonly use Okular instead of.
- Adobe Acrobat Reader
Similar apps
More open-source PDF editors and tools
Clop
FuzzyIdeas/Clop
Clop Image, video, PDF and clipboard optimiser Copy large, paste small, send fast As long as the Clop app is running, every time you copy an image to your clipboard, Clop will optimise it to the…
Active · last commit Oct 16, 2026
PDF editors & toolsmacOSPDF4QT
JakubMelka/PDF4QT
PDF4QT is an open-source PDF toolkit for Windows and Linux, combining powerful desktop applications, command-line tools and a modern MIT-licensed C++/Qt PDF engine.
Active · last commit Oct 18, 2026
PDF editors & toolsWindowsLinuxTRex
amebalabs/TRex
Copy any text on your screen, stop retyping.
Maintained · last commit Sep 29, 2026
OfficialPDF editors & toolsmacOSGromit Mpx
bk138/gromit-mpx
Gromit-MPX is an on-screen annotation tool that works with any Unix desktop environment under X11 as well as XWayland.
Maintained · last commit Sep 1, 2026
PDF editors & toolsLinuxgImageReader
manisandro/gImageReader
A Gtk/Qt front-end to tesseract-ocr.
Active · last commit Oct 27, 2026
PDF editors & toolsWindowsLinuxGradia
AlexanderVanhee/Gradia
Make your screenshots ready for all.
Maintained · last commit Sep 30, 2026
PDF editors & toolsLinux
Is Okular free and open source?
Yes. Okular's source code is public on GitHub under the GPL-2.0-or-later license, which is OSI-approved or FSF-free, so you can use, copy and change it for free.
How do I install Okular?
Download it from the project website or build it from source by following the README on GitHub.
Can Okular replace Adobe Acrobat Reader?
Okular is commonly used as a free alternative to Adobe Acrobat Reader. Features differ, so check that it opens the file formats and covers the workflows you rely on before switching.