Thorium Reader
Thorium Reader: A free, accessible reader for EPUB, PDF, DAISY, and Web Publications. Ranked #4 of 27 in Ebook Reader Software by our editors (8.9/10); pricing: Free plan; best for accessible desktop reading with DRM support.
At a glance
- Editor score8.9 / 10
- PricingFree plan
- Best forAccessible desktop reading with DRM support
- Free planYes
- Paid fromFree
- Annotation toolsYes
- Facts checked22 Sep 2026
Where it wins
- Supports EPUB, PDF, DAISY, and Web Publications
- Includes annotations, bookmarks, search, and offline reading
- Offers keyboard navigation and screen-reader support
Where it doesn't
- Offline reading applies to downloaded publications
- OPDS browsing depends on available catalogs
- Readium LCP support is limited to protected LCP publications
Our verdict on Thorium Reader
Thorium Reader is a free digital reading application and personal library for ebooks, audiobooks, comics, manga, and documents. It is suited to readers who need broad accessibility support, offline access, and compatibility with EPUB, PDF, DAISY, and Web Publications. The application runs on Windows, macOS, Linux, iOS, and iPadOS, making it relevant for desktop and mobile reading across common personal devices. EDRLab develops and maintains the application as a nonprofit focused on open standards, literacy, and accessibility.
Thorium Reader’s pricing is straightforward: the application is free across its supported platforms, with no paid tiers described. The free product includes library organization, customizable text size, themes, spacing, fonts, and reading modes. Readers can add, edit, tag, export, and import bookmarks, create annotations with comments and tags, search within ebooks, and navigate search results. Downloaded publications can be read offline, which suits users who want local access without requiring a continuous connection. Its documented format coverage is broad for reading-focused software, including EPUB 2 and 3, Fixed Layout EPUB, PDF, DAISY 2.02 and 3, and Web Publications.
The ecosystem fit is a key strength. Users can browse and download content from OPDS catalogs, access Project Gutenberg and LibriVox content, and open Readium LCP-protected publications. Accessibility features include keyboard navigation and screen-reader support, while reading settings can be adjusted for different preferences. Choose Thorium Reader if accessible reading, open standards, DRM support, annotations, and offline access matter more than a paid service layer. Readers who need downloaded content organized across a wider set of formats or who depend on an ecosystem outside its documented standards should consider whether its supported formats and catalog connections fit their library.
Your product? Our editors can test Thorium Reader in depth and publish a review, labelled as paid · from $149/mo →
Thorium Reader pricing
Thorium Reader fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| Supported platforms | Windows, macOS, Linux, iOS, iPadOS |
| Supported formats | EPUB 2/3, Fixed Layout EPUB, PDF, DAISY 2.02/3, Web Publications |
| Annotation tools | Yes |
| Reading sync | Not verified |
| Offline reading | Yes |
| Library storage | Not verified |
| Deployment | Desktop, Mobile |
| Platforms | Windows, macOS, Linux, iOS |
| Support | Email, Tickets, Community, Docs |
| Built for | Solo, Small business (editorial estimate) |
| Integrations | 4 integrations: OPDS catalogs, Readium LCP, Project Gutenberg, LibriVox |
| Pricing | Free plan |
| Website | thoriumreader.com |
| Facts checked | 22 Sep 2026 |
Thorium Reader integrations
Thorium Reader lists 4 integrations on its own site.
- OPDS catalogs
- Readium LCP
- Project Gutenberg
- LibriVox
Alternatives to Thorium Reader
- ReadestA cross-platform ebook reader for broad format support and detailed annotations.9.4
- BookFusionA flexible cloud library for mixed-format readers who want offline access and sync.9.2
- PocketBook ReaderA format-rich free reader for mobile users who need Adobe DRM and reading-position sync.9.0
See all Thorium Reader alternatives →
Thorium Reader vs the competition
- Thorium Reader vs Readest
- Thorium Reader vs BookFusion
- Thorium Reader vs PocketBook Reader
- Thorium Reader vs Moon+ Reader
- Thorium Reader vs KOReader
- Thorium Reader vs eBoox
Compare Thorium Reader with any tool side by side →
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Featured on iTechGuides
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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