KOReader

KOReader is a ebook reader application developed by F-Droid Open Source, packaged as a single Android APK of version 0.0 weighing in at 27.83 MB. The package targets Android 4.1+ and above. Below you'll find the publisher's own description, a quick spec sheet, and a short buyer-beware checklist so you know exactly what you're installing before tapping download.

1. Only download through the button on this page — never from third-party mirrors or shortened links, which are the most common way malware spreads.
2. File size is a light 27.83 MB, so it installs quickly even on modest connections.
3. This build is signed by "F-Droid Open Source" — always verify the developer name matches what's listed on the app's official store page before installing an update.
4. After install, Android may prompt you to allow "Install from unknown sources" — approve only this one install, then revoke the permission in Settings > Apps > Special access.
5. We link directly to the APK file or the publisher's repository; we do not modify the binary. Always run a virus scan after any sideloaded install.

KOReader is an ebook reader optimized for e-ink screens. It can open many formats and provides advanced text adjustments.

See below for a selection of its many features:

• Supports both fixed page formats (PDF, DjVu, CBT, CBZ) and reflowable e-book formats (EPUB, FB2, Mobi, DOC, CHM, TXT, HTML). Scanned PDF/DjVu documents can be reflowed. Special flow directions for reading double column PDFs and manga.


• Multi-lingual user interface optimized for e-ink screens. Highly customizable reader view with complete typesetting options. Multi-lingual hyphenation dictionaries are bundled in.


• Non-Latin script support for books, including the Hebrew, Arabic, Persian, Russian, Chinese, Japanese and Korean languages.


• Unique Book Map and Page Browser features to navigate your book.


• Special multi-page highlight mode with many local and online export options.


• Can synchronize your reading progress across all your KOReader running devices.


• Integrated with Calibre, Wallabag, Wikipedia, Google Translate and other content providers.

Is KOReader free to download?
Yes. The APK file linked from this page is free. The developer may offer in-app purchases once installed, but obtaining the installer itself costs nothing.

What Android version does KOReader require?
Android 4.1+ or newer. Installing on older devices may cause crashes or refuse to install.

Is KOReader safe to install?
We link to the exact APK published by F-Droid Open Source. We do not modify the file. Still, as with any sideloaded app, scan it with a reputable antivirus before opening it, and only grant permissions the app genuinely needs.

How do I update KOReader?
Install the newer version on top of the old one — Android will keep your data. If the signature differs, uninstall first (you may lose local progress).

Why is the app not installing?
Common causes: not enough storage, an older Android version than 4.1+, or a conflicting build already installed. Free up space, check your OS version, and uninstall any previous copy before retrying.

1. Tap the Download APK button above and save the file to your device.
2. Open your device Settings → Security (or Apps → Special access → Install unknown apps) and allow your file manager or browser to install unknown apps for this one file only.
3. Open the downloaded org.koreader.launcher.fdroid.apk file from your Downloads folder.
4. Tap Install and wait for Android to finish.
5. Open «KOReader» by F-Droid Open Source and grant only the permissions it actually needs.
6. Revoke the "unknown sources" permission once you are done installing.

Note: this page hosts or links to the installer only. The application name, icon and description are provided for identification. All trademarks belong to their respective owners.