When comparing FBReader vs Sumatra PDF, the Slant community recommends Sumatra PDF for most people. In the question“What are the best desktop readers?” Sumatra PDF is ranked 4th while FBReader is ranked 6th. The most important reason people chose Sumatra PDF is:
Including PDF, XPS, DjVu, CHM, EPUB, Mobi, FictionBook, PalmDoc, and comic books.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Built in eBook store
FBReader features an in built eBook store for users to download eBooks onto their devices through the app.
Pro Simple and fast
FBReader, while offering many options is simple in design, with that allowing for fast use.
Pro Books can be saved to SD card
Pro Cloud sync
FBReader has built in Google Drive sync for the users files, allowing them to store their eBooks online, not taking up room on their local storage.
Pro Reads many file types
Including PDF, XPS, DjVu, CHM, EPUB, Mobi, FictionBook, PalmDoc, and comic books.
Pro Book updates on the fly
If Book font, style is changed, Sumatra will take the update instantly, No need to close first and import again! Huge time saver for self publishing.
Pro Portable
The application consists of a single file that can be run without installation. You can put it on an external device, such as an usb thumb stick and run it on any Windows machine from the thumb stick.
Pro Multilingual
It's available in 69 languages.
Pro Free and open source
Sumatra is available for free, licensed under GPL with source code available on GitHub.
Cons
Con Cannot search for books on a SD card
Con No light mode
Unusable if you have astigmatism.
Con UI is bad
User interface is confusing and ugly.
Con Complex and confusing app settings
Con Windows only
No Linux or OSX versions available.