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Preview of EPUB Ninja - eBook Reader

EPUB Ninja - eBook Reader by Digital Fracture

A fast, lightweight EPUB and CBZ reader in your browser sidebar. Import books and comics, pick up where you left off, and read without distractions. 100% local your files never leave your browser.

Some features may require paymentSome features may require payment
Available on Firefox for Android™Available on Firefox for Android™
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About this extension
EPUB Ninja is a clean, distraction-free eBook and comic reader that lives in your Firefox sidebar. Import your EPUB and CBZ files, and start reading no cloud, no tracking.

FEATURES

• Sidebar eBook Reader: Read EPUBs right inside Firefox. No separate app needed.
• CBZ Comic Support: Import comic book archives with single page, two-page spread, and fullscreen viewing modes.
• Book Library: Manage your collection with cover art, reading progress, and sort by recent, title, or progress.
• Dark & Light Themes: Full dark mode that themes the entire browser chrome to match.
• Table of Contents: Slide-out chapter navigation. Jump to any section instantly.
• Bookmarks: Bookmark any chapter and return to it with one click.
• Full-Text Search: Search across every chapter of your book.
• Reader Settings: Font size, font family, line height, margins, text alignment, and paragraph spacing.
• Keyboard Navigation: Arrow keys to navigate, F for fullscreen, 1/2 for page modes, Escape to close panels.
• Reading Progress: Automatically saved. Close the browser and pick up exactly where you left off.
• 100% Local: All data stored in your browser. Books never leave your device. No servers, no uploads, no tracking.

SUPPORTED FORMATS

• EPUB 2 and EPUB 3 (eBooks)
• CBZ (Comic Book ZIP archives)

HOW IT WORKS
  1. Click the EPUB Ninja icon in your toolbar to open the sidebar.
  2. Click "Import EPUB / CBZ" and select your files.
  3. Click a book to start reading.

Your books are stored locally in IndexedDB and browser storage. Nothing is sent anywhere.

Part of the Ninja suite from the makers of RSS Ninja.

Website: https://rssninja.co.uk
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Permissions and data

Required permissions:

  • Access browser tabs

Optional permissions:

  • Access your data for rssninja.co.uk

Data collection:

  • The developer says this extension doesn't require data collection.
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More information
Add-on Links
  • Homepage
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Version
1.0.2
Size
1.38 MB
Last updated
8 days ago (Apr 6, 2026)
Related Categories
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License
Mozilla Public License 2.0
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