KOReader is a document viewer primarily aimed at e-ink readers.

Download • User guide • Wiki • Developer docs

Main features

• portable: runs on embedded devices (Cervantes, Kindle, Kobo, PocketBook, reMarkable), Android and Linux computers. Developers can run a KOReader emulator in Linux and MacOS.

• multi-format documents: supports fixed page formats (PDF, DjVu, CBT, CBZ) and reflowable e-book formats (EPUB, FB2, Mobi, DOC, CHM, TXT). Scanned PDF/DjVu documents can also be reflowed with the built-in K2pdfopt library.

• full-featured reading: multi-lingual user interface with a highly customizable reader view and many typesetting options. You can set arbitrary page margins, override line spacing and choose external fonts and styles. It has multi-lingual hyphenation dictionaries bundled into the application.

• integrated with calibre (search metadata, receive ebooks wirelessly, browse library via OPDS), Wallabag, Wikipedia, Google Translate and other content providers.

• optimized for e-ink devices: custom UI without animation, with paginated menus, adjustable text contrast, and easy zoom to fit content or page in paged media.

• extensible: via plugins

• fast: on some older devices, it has been measured to have less than half the page-turn delay as the built in reading software.

• and much more: look up words with StarDict dictionaries / Wikipedia, add your own online OPDS catalogs and RSS feeds, over-the-air software updates, an FTP client, an SSH server, …

Please check the user guide and the wiki to discover more features and to help us document them.

Screenshots

Installation

Please follow the model specific steps for your device:

Android • Cervantes • Kindle • Kobo • Linux • Pocketbook • reMarkable

Development

Setting up a build environment • Collaborating with Git • Building targets • Porting • Developer docs

Support

KOReader is developed and supported by volunteers all around the world. There are many ways you can help:

• fix bugs and implement new features
• translate the program into your language or improve an existing translation
• document lesser-known features on the wiki
• help others with your knowledge on the forum

Right now we only support liberapay donations, but you can also create a bounty to motivate others to work on a specific bug or feature request.

Contributors