Choosing an Open-Source E-Reader: What Fits Your Reading Habits

If you read on an e-ink device, look at KOReader, which runs on Kindle, Kobo, PocketBook, reMarkable, and Cervantes devices as well as Android and Linux. To manage a book collection on a computer, use calibre. For a modern reading app that syncs across your phone and computer, try Readest. For LCP-protected library e-books on a computer, Thorium Reader is the one to check.

"Open-source e-reader" usually means open-source reading software rather than an open-source device. The comparison below covers the software, then the self-hosted servers that hold a library, then the hardware question. Facts were checked on October 13, 2026, from each project's own site or repository.

Reading apps compared

KOReader

KOReader's README lists support for fixed-layout formats (PDF, DjVu, CBT, CBZ) and reflowable formats (EPUB, FB2, Mobi, DOC, RTF, HTML, CHM, TXT). It can also reflow scanned PDF and DjVu documents so they fit a small screen, which matters if you read scanned papers on a 6-inch device. Installation is different on each device, and the project's wiki has a separate guide for each platform, including Android, Kindle, Kobo, and PocketBook. On a Kindle, the wiki says KOReader can be installed only on jailbroken devices.

calibre

calibre describes itself as "a powerful and easy to use e-book manager" and says it is completely free and open source. It manages your library, converts between dozens of file types, sends books to reading devices over a cable or wirelessly, and includes a viewer. It can also run a web server that lets you read or share your library from a browser. Downloads are available for Windows, macOS, and Linux.

Readest

Readest is a newer reading app that its README calls a modern rewrite of Foliate. It syncs book files, reading progress, notes, and bookmarks across platforms, and it can sync progress with KOReader devices. On Apple devices it installs from the App Store; for Windows, Linux, and Android it is downloaded from the project's site or GitHub releases.

Thorium Reader

Thorium Reader, from EDRLab, is an EPUB reading app for Windows 10, macOS, and Linux, and it can import books from a folder or an OPDS catalog. It can open LCP-protected books, a DRM system that EDRLab offers for library lending and bookstore sales, but only through an extra component that is not in the open-source code. If you build Thorium from source yourself, it can open only books protected with LCP's "Basic Encryption Profile," because the production-grade LCP library is not included.

Foliate and Plato

Foliate is a GTK reading app for Linux, available on Flathub and the Snap Store. Plato is a document reader made specifically for Kobo e-readers and reads EPUB through its own built-in renderer. Both repositories live under individual developers' GitHub accounts, so check them for recent activity before you rely on either.

Self-hosted servers for your library

If you keep books on a home server or NAS, a reading server lets you browse and read them from any device:

• Kavita (GPL-3.0) is a cross-platform reading server for books, comics, and manga.
• Komga (MIT) is a media server for comics, manga, magazines, and e-books, with an API, OPDS, Kobo Sync, and KOReader Sync support.

Both pair well with the storage options in our guide to open NAS software. calibre's built-in web server is a simpler option if you already use calibre.

What about an open-source e-reader device?

One example of open e-reader hardware is The Open Book by Joey Castillo, an open source hardware e-book reader whose repository is licensed CC-BY-SA-4.0. Its most recent commit, on any branch, is from December 2023, so treat it as a build-it-yourself project rather than something you can buy.

For most people, the practical route to an open reading experience is a mainstream e-ink device running KOReader or Plato. Check the KOReader wiki for your exact model before you buy, because support differs between models.

How to choose

1. Decide where you read. An e-ink device points to KOReader or Plato. A phone and computer together point to Readest. A Linux desktop points to Foliate.
2. Check your file formats. If you read many PDFs or scanned documents, KOReader's reflow option is the deciding feature.
3. Think about DRM. calibre's FAQ says most purchased EPUB books have DRM that prevents calibre from opening them, and KOReader's Kindle guide says it does not support DRM-protected books. Thorium's official builds can open LCP-protected books.
4. Decide how you organize books. calibre handles library management on a computer, and Kavita or Komga handle it on a server.