The Universal Document Viewer
Multi-platform, fast and packed with features, Okular allows you to read PDF documents, comics and EPub books, browse images, visualize Markdown documents, and much more.
Support for Many Formats
Okular supports many formats, including PDF, EPub, DjVU and MD for documents; JPEG, PNG, GIF, Tiff, WebP for images; CBR and CBZ for comics; and many, many more.
Advanced User Interface
Okular has a wide range of features that lets you easily manage your documents.
Annotate your PDFs
With Okular's 'Annotation mode', you can easily add inline and popup notes, highlight and underline text, or even add your own text.
Select and View any Text
With Okular's 'Selection mode', you can copy and paste almost anything from your documents to elsewhere. And, for those times the text you want to read is too small, you can use the 'Magnifier mode'.
Your Content, at a Glance
Navigating your content is easier than ever. With Okular's 'Thumbnails panel', you can browse graphically the part of the document you were looking for. With the 'Content panel', find the chapter you need in all supported documents.
First-class Signature Support
You can view and verify digital signatures embedded in PDFs, check if they are still valid, and detect any modifications since the moment the document was signed. You can even sign PDFs yourself!
Okular is released under the GPLv2, and is thus fully Free Sofware.