Open-Source Ebook Readers : a roundup

In the digital age, reading ebooks has become a common way of enjoying literature. Ebooks are way cheaper than its printed counterpart. They’re lightweight, portable and improve our reading experience. You can even adjust the look and feel of the book, something that printed books can never offer.

There are many ebook standards and consequently many ebook formats. We have the infamous PDF, ePub, Mobi, DjVU, etc, plus the AZW format and its variation. While most platform supports PDF out of the box, other formats need a ebook reader software for them.

This article feature the best open source ebook readers that provide extensive support for a wide range of ebook formats.

Calibre – the most popular ebook reader and manager


Calibre is already a favourite open source ebook reader of many bookworms. With a relatively easy to use interface, the software offer a surprisingly large number of advanced features. You can manage, read, edit, convert, add/edit metadata as well as connect and sync ebooks with a variety of ebook readers.

Calibre supports reading a huge number of ebook formats : AZW, AZW3, AZW4, CBZ, CBR, CB7, CBC, CHM, DJVU, DOCX, EPUB, FB2, FBZ, HTML, HTMLZ, LIT, LRF, MOBI, ODT, PDF, PRC, PDB, PML, RB, RTF, SNB, TCR, TXT, TXTZ.

You can also edit EPUB and AZW3 ebooks using Calibre. Other formats like MOBI or PRC needs to be converted before it can be edited.

If your ebook reader supports a limited number of formats, you are able to convert other formats into it using Calibre. Supported formats are AZW3, EPUB, DOCX, FB2, HTMLZ, OEB, LIT, LRF, MOBI, PDB, PMLZ, RB, PDF, RTF, SNB, TCR, TXT, TXTZ, ZIP.

Calibre runs on most major platforms, including Windows, Linux, MacOS, FreeBSD.

Website :

Source code :

SumatraPDF – a PDF reader that happens to read other formats


Despite what the software name says, Sumatra PDF can actually reads other ebooks formats like EPUB, MOBI as well as XPS, DjVu, CHM, CBZ, CBR, FB2.

SumatraPDF runs on Windows only. Support for Windows XP ended with version 3.1.2.

Website :

Source code :

Foliate – a simple and modern ebook reader


Foliate is a new open source ebook reader built on the back of modern technologies like GJS and Epub.js.

The software supports a handful of ebook formats such as EPUB, AZW, AZW3, MOBI, FB, FB2, CBR, CBZ, CBT, CB7 and plain TXT files. The interface is minimal but feature-packed. You can adjust font, line spacing, margins, bookmarks, annotate ebooks. You can also view ebook in single-column or two column layout. Foliate even supports text-to-speech with external engine like eSpeak NG and Festival and look up words in Wiktionary, Wikipedia, dictd, and sdcv, or translate text with Google Translate.

Foliate runs on Linux only and have pre-built packages for Arch Linux, Fedora, Manjaro, Ubuntu and Void Linux.

Website :

Source code :

Lector – a Qt based open source ebook reader

Lector - a Qt based ebook reader

Lector is an open source ebook reader that emphasizes minimal design. The software currently support a handful of ebook formats, such as PDF
, EPUB, DJVU, FB2, MOBI, AZW / AZW3 / AZW4, CBR / CBZ, Markdown.

Lector is implemented using Python and PyQt. To enable support for a few ebook format, you need to install external depencies. PDF support depends on python-pymupdf, DjVu – python-djvulibre, Markdown relies on python-markdown and TXT via textile. You should install the depencies using a package manager before getting to install

Lector runs on Linux only and have pre-built packages for Arch Linux, Fedora, openSUSE and Gentoo.

Download :

Bookworm – an elementary OS style ebook reader

Bookworm - an elementary OS style ebook reader

Bookworm is a open source ebook reader developed specifically for elementary OS and mimics its design language.

Currently Bookworm supports several ebook formats, including EPUB, PDF, MOBI, FB2, CBR, CBZ. Major features including text zoom in/out, margin increase/decrease and line width increase/decrease, changing background color, Night Mode, view space caching and more.

Bookworm was targeted at elementary OS users, but it runs just fine on other operating system as long as it’s a Debian or Ubuntu based OS. Details about its installation can be found in Bookworm’s official website.

Website :

Source code :

Cool Reader

Cool Reader - open source, cross-platform ebook reader

CoolReader is a fast and lightweight cross-platform eBook reader for desktops and handheld devices.

Currently, CoolReader supports the following ebook formats : FB2, TXT, RTF, DOC, TCR, HTML, EPUB, CHM, PDB, MOBI. The software runs on Windows, Linux and Android. There are alsod a few ported versions for e-ink based devices.

Website :

Koodo Reader

Koodo Reader - Javascript based, cross platform open source ebook reader

Koodo is a cross-platform ebook reader that supports viewing EPUB , PDF, MOBI, AZW3 and TXT. Written in JavaScript, the software runs on most major platforms, including Windows, Linux, MacOS and Web-based. Its feature list reads as follows :

  • Book syncing with Dropbox or through WebDAV
  • Customize the source folder and synchronize multiple devices using OneDrive, iCloud, Dropbox, etc.
  • Single-column, two-column, or continuous scrolling layouts
  • Text-to-speech, Translation
  • Bookmark, Note, Digest, Shelf and Tag
  • Adjust font, line-spacing, background color, text color and margins
  • Support for Touch Screen
  • Text highlight and underline
  • Language support: Simplified Chinese, Traditional Chinese and English

Website :

Source code :

Android Book Reader

Android Book Reader

If you’re a developer who are looking for examples of an Android ebook reader, you may find this project interesting. The software is a simple Android app that supports reading a handful of ebook formats, including FB2, HTML, TXT, EPUB, MOBI, RTF, DOC, PDF, DJVU, CBR, CBZ. It was built on the back of other open source projects such as FBReader, Pdfium, Djvulibre, K2PdfOpt.

Download and source-code :

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