Reading EPUB eBooks on Ubuntu is straightforward once you pick the right reader and installation method. This guide walks through the best choices for Ubuntu users, precise install commands for different packaging systems, exact steps to open EPUB files graphically and from the terminal, file conversion options, common problems and fixes, plus practical pro tips and a full FAQ to get you confidently reading EPUBs on any Ubuntu release.
EPUB is a widely used open eBook format, supported by many Linux-native applications. Some apps focus on library management and conversion, while others provide a lightweight, distraction-free reading experience. Here you’ll learn how to install, configure, and use the most reliable readers on Ubuntu — including Calibre, Foliate, Okular, Bookworm, Thorium Reader, and FBReader — and how to handle DRM-free EPUBs safely.
Before proceeding with installation steps, make sure your Ubuntu installation is up to date and that you know whether you prefer system packages (APT), containerized packages (Snap / Flatpak), or portable ones (AppImage). Each approach has tradeoffs in update frequency, sandboxing, and integration with your desktop environment.
Supported sources and references: official project pages for Calibre, Foliate (Flathub / Snap), Ubuntu package documentation, and manual pages for calibre command-line tools provide authoritative installation commands and usage examples used throughout this guide.
Which EPUB Reader Should You Choose?
Different readers target different needs: full library and conversion, lightweight reading, or accessibility features. Below is a quick comparison to help you match software to your workflow.
Calibre — power user library manager
Calibre is a comprehensive eBook library manager, converter, and reader. It handles huge libraries, metadata editing, format conversion, and an optional content server to serve books to other devices. It is the go-to solution when you need conversions (EPUB ↔ MOBI/PDF), batch processing, or a web server for remote access.
Foliate — modern, minimal reader
Foliate focuses on an elegant reading experience with a modern GTK user interface, theme options (light/sepia/dark), annotations, dictionary lookup, and both paginated and scrolled modes. It’s ideal for everyday reading without heavy library management overhead.
Okular, Bookworm, Thorium, FBReader — alternatives
Okular (KDE) and Bookworm (GNOME) offer integrated desktop viewers with decent EPUB support. Thorium Reader is accessibility-focused with DRM-aware builds, and FBReader is lightweight and cross-platform. Choose these if you want a simple viewer integrated into your desktop environment or a specific accessibility feature set.
Preparing Ubuntu: Update, Snap, Flatpak (Optional)
Start by updating packages and deciding whether to use Snap or Flatpak for certain readers. Snap and Flatpak provide up-to-date builds independent of distribution packages, which is handy if your Ubuntu release ships older versions.
Update package lists and upgrade security patches:
sudo apt update && sudo apt upgrade -y
If you plan to use Snap packages (for Foliate or others) ensure snapd is installed:
sudo apt install snapd
For Flatpak support (Flathub), install flatpak and add the Flathub remote:
sudo apt install flatpak
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
Installations: Exact Commands for Popular EPUB Readers
1) Install Calibre (recommended for conversions and library)
Calibre official Linux installer keeps Calibre current across Ubuntu releases. Use the one-line installer from the Calibre website to avoid old distribution packages:
sudo -v && wget -nv -O- https://calibre-ebook.com/dist/linux-installer.sh | sudo sh /dev/stdin
After installation, start Calibre from your applications menu or run:
calibre
2) Install Foliate (recommended for daily reading)
Foliate is available as a Flatpak on Flathub and as a Snap. For the most stable integration across GNOME desktops use Flatpak:
flatpak install flathub com.github.johnfactotum.Foliate
Or, to install via Snap:
sudo snap install foliate
Start Foliate from the applications menu or run:
flatpak run com.github.johnfactotum.Foliate
3) Install Okular, Bookworm, Thorium, or FBReader
Okular (KDE):
sudo apt install okular
Bookworm (GNOME):
sudo add-apt-repository ppa:bookworm-team/bookworm -y && sudo apt update && sudo apt install com.github.babluboy.bookworm
Thorium Reader offers downloadable AppImages and official Linux builds from its website; FBReader is available in repositories:
sudo apt install fbreader
How to Open an EPUB File — Graphical Methods
Once installed, opening EPUB files is typically a two-click process. Right-click the EPUB file, choose Open With, and select your installed reader (Calibre, Foliate, Okular, etc.). To make a reader the default for all EPUB files:
- Right-click an EPUB file and choose Properties.
- Go to the Open With tab.
- Select your preferred reader and click Set as default.
If your reader does not appear in the menu, use the application’s launcher or open the program and use File → Open to browse to your EPUB.
Tip: Some file managers show EPUB as an archive; ensure the file has a proper .epub extension and is not corrupted.
How to Open an EPUB File — Command Line and Server Options
Open EPUB with Calibre’s eBook viewer from the terminal
Calibre includes a lightweight viewer if you prefer starting books from the command line. Use:
ebook-viewer /path/to/book.epub
This launches Calibre’s reader directly without the full library interface.
Convert or batch-process EPUB files
Calibre’s command-line tools enable conversion and automation. Convert EPUB to PDF or MOBI:
ebook-convert input.epub output.pdf
Batch conversions can be scripted with a simple loop in bash for many files.
Serve your library with Calibre Content Server
If you want to access EPUBs from other devices, Calibre’s content server provides a web interface:
calibre-server --with-library /path/to/library
Visit the displayed local URL in a browser or open remotely if you expose the server securely.
Handling Common EPUB Issues and DRM
Problem: EPUB won’t open or shows errors
Corrupted EPUBs may fail to open. Try re-downloading the file and check the file size. If a reader reports parsing errors, attempt opening the file in Calibre which is tolerant and can often identify structural issues.
Problem: EPUB has DRM
Commercial EPUB files bought from certain stores may include DRM. Ubuntu readers typically cannot open DRM-protected files without vendor-specific apps or authorized devices. The legitimate approach is to use vendor apps or re-download DRM-free versions where the vendor provides them. Do not attempt to remove DRM unless you have legal permission and comply with local copyright laws.
Problem: Fonts or layout look wrong
Change rendering options in your reader: switch between paginated and scrolled modes, pick a different font family or size, or disable embedded fonts if the reader supports it. Foliate and Calibre both provide per-book and global display settings for fine control.
Practical Workflows and Useful Commands
- Open a book quickly: Use xdg-open /path/to/book.epub to open with the system default reader. This works across desktop environments and respects your Default Applications setting.
- Search for ebooks in a directory: Use find ~/Books -iname “*.epub” to list EPUB files across directories. Combine with xargs to open or convert multiple files.
- Batch convert to PDF: Use a loop: for f in *.epub; do ebook-convert “$f” “${f%.epub}.pdf”; done. This converts every EPUB in the current folder to PDF.
- Run Calibre Content Server on boot: Create a systemd unit or use Docker to run the server as a service for stable remote access from phones and tablets.
- Use Flatpak versions for newest features: If your Ubuntu release lags behind, the Flatpak or Snap version of Foliate often includes newer features sooner than apt repositories.
Pro Tips
- Prefer Flatpak or Snap for the latest Foliate: If you use newer EPUB features or bugfixes, Flatpak/Snap builds are updated faster than distribution repositories. They also sandbox the app for added safety.
- Keep a small, local Calibre library: Use Calibre for heavy lifting (conversion, metadata, content server) and a lightweight reader (Foliate) for daily reading to keep your desktop uncluttered and fast.
- Use bookmarks and annotations wisely: Readers like Foliate and Calibre support annotations; export notes periodically if you need them across devices.
- Automate with scripts: If you frequently convert or normalize EPUBs, write short shell scripts to normalize file names, metadata, and formats with Calibre CLI tools.
- Test accessibility features: Thorium Reader is a strong alternative when accessibility or Readium LCP support is required for institutional EPUBs.
Frequently Asked Questions
Can I open Kindle files on Ubuntu?
Kindle’s native format is different and DRM-protected Kindle books require Amazon’s Kindle software or authorized devices. Some Kindle files (AZW3, MOBI) can be opened in Calibre if DRM is not present. For purchased Kindle books, check vendor options for DRM-free downloads or authorized apps.
Is converting EPUB to PDF lossy?
Converting EPUB to PDF can change layout and reflow; EPUB is reflowable while PDF is fixed layout. Expect differences in pagination, fonts, and image placement. Calibre offers conversion options to tune output, but exact fidelity is not always possible.
Why won’t Foliate or other readers appear in the Open With list?
If the reader is installed as Flatpak/Snap it may not register with the traditional desktop integration immediately. Restart your session or run the Flatpak/Snap command to launch the app once; it usually appears in the Open With menu afterwards.
How do I open multiple EPUBs at once?
Many GUI readers open one book per window; Calibre manages libraries and can browse multiple. From the command line, you can open several files by listing them: ebook-viewer book1.epub book2.epub, or script batch operations with loops.
Are EPUB readers safe to install from Flathub / Snap?
Flathub and the Snap Store are widely used and generally safe. They provide sandboxing, and apps are maintained by projects or maintainers. Prefer official Flathub/Snap packages for reliability and updates if you want the newest features.
Conclusion
Opening EPUB files on Ubuntu is simple once you choose the right reader and installation path. For power users and conversion needs, Calibre is unmatched for library management and file format conversion. For daily reading, Foliate offers a modern, distraction-free experience available via Flatpak or Snap. Okular, Bookworm, Thorium, and FBReader provide capable alternatives depending on desktop environment preferences or accessibility requirements. Use Calibre’s command-line tools for automation and content serving, and select Flatpak/Snap when you want more up-to-date builds independent of Ubuntu’s package timelines. Keep security and DRM legality in mind: avoid tools or steps that infringe on copyright. With the commands, workflows, and troubleshooting steps above you should be able to open, convert, and manage your EPUB collection on Ubuntu reliably.
