Thorium Reader

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 localised in a large set of languages, each version offering new locales.

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

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

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

Download and Use Thorium Reader

The latest version of Thorium Reader is 2.4.2, released in May 2024.

This version features:

  • Improved text highlighting engine and several under the hood improvements (performance, accessibility, operating system integration, etc.)
  • Handling of diacritics in the “find text” / “search” feature
  • Better support for vertical writing mode and right-to-left (RTL) direction
  • New option to disable RTL inversion in the user interface
  • Adds Slovenian/Slovenščina and Danish/Dansk, update Portuguese (Portugal) and Swedish, fix bug with the variants of Chinese (traditional vs. simplified) and Portuguese (Portugal vs. Brazil)
  • Support for proof-of-concept sign language EPUB3 Media Overlays

Download links and full documentation in English and French are now available from a dedicated landing page.

Windows users can download the application from the Windows Store.

Please Donate for 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


“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)

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

Public 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.

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.

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.

Other Readium projects

Readium Mobile

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

More on Readium Mobile

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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