EPUB Ninja - eBook Reader Firefox

EPUB Ninja - eBook Reader

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.

Features & Capabilities

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

User Growth & Download Statistics

Manifest V3 Add-on
By:
Digital Fracture
Daily users:
59
Version:
1.0.2 Last updated: 2026-04-09
Version code:
6210639
Creation date:
2026-04-05
Risk:
Moderate risk impact High risk likelihood
Permissions:
Host permissions:
  • https://rssninja.co.uk/*
Size:
1.38MB
Email:
ex*****@digitalfracture.co.uk
URLs:
Website ,Privacy policy
Full description:
See detailed description
Source:
Firefox Add-ons Store
Data ingested on:
2026-08-16
Compare stats and ranking:

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.
Developed by:
Digital Fracture
Firefox Add-ons Store
https://addons.mozilla.org/firefox/addon/epub-ninja-ebook-reader/
Email:
ex*****@digitalfracture.co.uk
Website:
https://www.digitalfracture.co.uk

Is EPUB Ninja - eBook Reader Safe?

Risk impact
Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

EPUB Ninja - eBook Reader requires a few sensitive permissions. Exercise caution before installing.

Risk impact analysis details
  • Critical Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
  • Low ******* ****** ** *** ********* ******** *****
Risk likelihood
Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

EPUB Ninja - eBook Reader may not be trust-worthy. Avoid installing if possible unless you really trust this publisher.

Risk likelihood analysis details
  • High This extension has low user count. Unpopular extensions may not be stable or safe.
  • Medium **** ********* *** ***** ** *** **** * ******* *** ********** *** *** ** ****** ** *****
  • Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
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