Okular
Document viewer for PDFs, ebooks and comics, with highlighting, notes and form filling.
Our verdict
Okular is the sensible replacement for Adobe Acrobat Reader. It opens everything Reader does and adds comics and ebooks, and it does all of it without an account, a sign-in prompt or an upsell.
Marking up documents works well. You can highlight, underline, add a popup note or draw on a page, then save those marks into the PDF so the person you send it to sees them.
What it does not do is rewrite a PDF. Changing the words in an existing document needs a different tool. For shuffling and merging pages, PDF Arranger is the companion piece. For handwritten annotation with a stylus, Xournal++ is better suited.
What's good
- Highlights, sticky notes and freehand marks on PDFs, which the basic viewers cannot do
- Opens PDF, EPUB, DjVu, Markdown, images and comic book files in one program
- Fills in PDF forms and can check and create digital signatures
What to know first
- Notes are saved separately by default, so you must choose to save them into the PDF itself
- The toolbar carries a lot of buttons and takes a while to learn
- Editing the actual text of a PDF is not possible
The details
- Cost
- Free
- Open source
- Yes (GPL-2.0-or-later)
- How you install it
- App store (Flatpak), .deb installer, .rpm installer, Built-in app store
Windows apps it can replace
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