Ubuntu ships with LibreOffice (which opens PDFs into Draw, with mixed fidelity) and Evince (a viewer). Neither is a real PDF editor. The PPA-installed options have learning curves. Snap and Flatpak have a few editors but most have catches.
Firefox runs Flint. That covers it.
The Ubuntu PDF gap
Ubuntu has more PDF *viewers* than any OS — Evince, Okular, Atril, qpdfview — and almost no real PDF *editors*. LibreOffice Draw can edit PDFs by importing them, but layout shifts, fonts substitute, and tables sometimes break. For minor visual edits it's OK; for proper PDF editing it's a workaround.
Flint in Firefox treats PDFs as PDFs. Edit text inline, save back as PDF, no format dance.
Step by step on Ubuntu
Open Firefox. Go to flintpdf.com. Drag the PDF from Files (or your file manager of choice) into the editor. Click text to edit. Save the result to Downloads.
Sign, merge, compress, convert to Word all use the same browser tab.
Combining with CLI tools
For batch jobs on Ubuntu, command-line tools are king — qpdf for splitting, pdftk for merging (well, pdftk-java these days), Ghostscript for compression. Use them for scripted automation; use Flint for one-off interactive edits. They complement rather than compete.
FAQ
Will Flint work on Ubuntu LTS releases?
Yes. Any Ubuntu version with a current Firefox or Chrome runs Flint — that's 20.04 LTS, 22.04 LTS, 24.04 LTS, and current non-LTS releases.
Does Flint need any apt or snap install?
No. It's a web app. Open the URL in Firefox or Chrome and it runs. No installs, no PPAs, no Snap.
Can I use Flint on a server with no GUI?
Flint requires a graphical browser. For headless servers, use CLI tools (qpdf, pdftk) for PDF processing.
Skip LibreOffice's PDF dance. Edit PDFs in Firefox on Ubuntu.