FBReader vs Thorium Reader

FBReader is an ebook reader for Windows, macOS, Linux, Android, and iOS. It opens formats including ePub, fb2, mobi, HTML, RTF, and plain text, as well as ePub books protected with Readium LCP. Its Book Network can synchronize collections, reading positions, bookmarks, and custom shelves across supported devices. Books in the network are stored in the user's Google Drive space, while metadata, covers, and reading positions are stored on FBReader servers.

Online OPDS book catalogues are supported on Android, Windows, macOS, and Linux; iOS support is planned. Android Premium adds PDF and comics support, Google and DeepL translation integration, and automatic reading aloud. The free iOS version is limited to ten books and disables online translators. FBReader offers free plans for desktop, Android, and iOS; Android Premium is $14.99 as a one-time purchase. The company says its current code is closed source.

Thorium Reader is a free reader and library for ebooks, audiobooks, comics, manga, and documents. It runs on Windows, macOS, Linux, iOS, and iPadOS, with minimum versions listed by the maker. Supported material includes EPUB 2/3, fixed-layout EPUB, PDF, DAISY, Web Publications, audiobook formats such as MP3 and FLAC, and comics in CBZ, EPUB, or PDF. The app opens DRM-free publications and Readium LCP-protected titles from compatible retailers or libraries. Downloaded items work offline, although LCP files need an online connection at least once. Readers can change text size, themes, spacing, and fonts, and use keyboard navigation with custom shortcuts. Accessibility support includes JAWS, NVDA, Narrator, and VoiceOver; the iOS statement notes VoiceOver limitations for EPUB and PDF reading. Desktop users can browse OPDS catalogs when providers allow it. EDRLab develops Thorium Reader, and support is offered through a Help Desk and Discord.