Thorium Reader

a woman sitting at a table reading at her smartphone

logo of Thorium Reader Thorium Reader is the EPUB reader of choice for Windows 10 and 11, MacOS and Linux.

This EDRLab application is in constant development and aims at becoming a reference for accessing EPUB 3 publications in reflow or fixed layout format, audiobooks and visual narratives, PDF documents and DAISY 2.02 and 3 accessible ebooks; LCP protected or not.

It is localized in a large set of languages, each version offering new locales.

Huge efforts are also made to get Thorium Reader highly accessible for visually impaired and dyslexic people.

This application is free, with no ads and no leaks of private data.

This is the perfect tools for heavy readers, library patrons and students.

You’ll find here a documentation in English and French.


“I love Thorium and have introduced it to my students for reading any digital content. It is doubly good when something that makes reading more accessible for visually impaired people is also something that makes things more flexible for all. It makes it so much easier to get buy-in for using it.” – Suzanne Norman (Simon Frazer University, Canada)

“I am very happy to have found this app. Its simple, easy to use, and most importantly, its very friendly for people who are blind and visually impaired.”  (Noberto, USA)

“I can’t get enough of this ebook reader its clean and simple makes things easier for me to read! thank you I totally recommend this!” (Gigi, USA)

Presentations of Thorium Reader

Daniel Weck made a presentation of the latest features of Thorium Reader during the Digital Publishing Summit 2023:

Here is the video are the of his presentation and the associated slidedeck.

To go further in your discovery, please check our Youtube Thorium Reader playlist.

NNELS (Canada) has also made a great demonstration of Thorium + NVDA during the Accessible Publishing Summit 2023.

Sponsor Thorium Reader

This software is free, open-source and as such, its development is only possible because it is funded by different organizations. Among these, members of EDRLab, private or public grants and small recurring donations from happy users (individuals or companies).

Make a small recurring donation via Github Sponsor
Make a one-shot 1000 € donation via Stripe

Terms of Use, Privacy Policy

Please read carefully the following terms and conditions and the documents incorporated by reference therein before you begin using the Thorium Reader application.

Terms of Use
Privacy Policy

Download Thorium Reader

The latest version of Thorium Reader is 2.3.0, released in August 2023.

This version features:

  • New and updated translations: Bulgarian, Greek, Croatian, Korean, Portuguese (Portugal).
  • Reader / image zoom: major feature update from initial proof of concept, better user experience (finger touch, trackpad gestures, mouse wheel, keyboard); support for raster/bitmap images as well as SVG markup.
  • Reader / MathML: native rendering; prioritization of authored alt-text if present, with the option to dig further / deeper into the MathML structure (useful with screen reader specialised plugins).
  • Reader / navigation history: hyperlink activation now correctly sets the landmark for previous/next navigation.
  • Reader / text display: fixed left/right/justify text alignement (“start” can be left or right depending on document language), “automatic” is now “default” with changed SVG icon to avoid confusion.
  • Reader / UX: finger swipe gesture can now be used to turn pages (requires touch screen).
  • Reader text selection: double-click now works (bookmarks label for now, later in upcoming annotations feature).
  • Reader / TTS: many fixes.
  • Reader / HTML5 audio: fixed visible controls visibility.

And many more, detailed in the release page.

Here are links to:

For testers willing to check our latest developments, nightly builds of the Windows, MacOS and Linux versions can also be downloaded from the EDRLab Github platform.

Need support?

As every open-source project, support is mainly done via Github issues.

Here is the link to the EDRLab Github Thorium Reader issues repository.

If your unable to open a Github issue for any reason, you can also send an email to thorium-support at (@ replaced to avoid spam), we’ll make our possible to answer.

Why developing Thorium Reader?

For a long time, there was no modern EPUB 3 compliant reading application usable on Windows, OSX and Linux, properly accessible for print disabled people, with a good support for the LCP DRM and capable of browsing OPDS catalogs.

EDRLab decided to build such an application and release it for free, in order to provide users a great way to enjoy on a large screen EPUB publications, comics / manga / bandes dessinées, audiobooks, LCP protected PDF documents.

Print disabled people now benefit from an EPUB 3 reading app which supports screen readers like Jaws and NVDA on Windows, Voice Over on Mac.


Thorium Reader is based on the set of open-source chrome-less modules, a toolkit named Readium Desktop. Thorium Reader and Readium Desktop both rely on Electron.js, node.js and typescript, which are efficient cross-platform technologies. Thorium is also using React components based on HTML 5/CSS 3.

Media coverage

Introducing Thorium, a new free desktop EPUB reader for Windows and Mac, 24th Annual Accessing Higher Ground, November 2019, speakers Richard Orme (CEO) and George Kerscher (Chief Innovations Officer), DAISY Consortium.

Thorium Reader, une application de lecture pour Windows, macOS et Linux, January 2020, Actualitté.

Le logiciel de lecture d’ePub pour Windows MacOS et Linux, Thorium Reader, est disponible, March 2020,

L’application Thorium Reader peut désormais lire les livres audio., April 2020, Actualitté.

Thorium Reader is a free cross-platform eBook reading app, May 2021, GoodEReader.

Other Readium projects

Readium Mobile

The reference iOS and an Android open-source reading toolkit.

More on Readium Mobile

woman in library reading at a tablet with lock in her hand

Readium LCP

The vendor-neutral and interoperableDigital Rights Management technology, embeddable in any reading application based on the Readium SDK.

Discover Readium LCP

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