The FictionBook format does not specify the appearance of a document; instead, it describes its structure. For example, there are special tags for epigraphs, verses and quotations. All ebook metadata, such as author name, title, and publisher, is also present in the ebook file. This makes the format convenient for automatic processing, indexing, and ebook collection management, and allows automatic conversion into other formats.
In contrast to other eBook formats (e.g. ePub), a FictionBook document consists of a single XML file. Images are converted to Base64 and reside inside the <binary> tag, so the size of the embedded images is increased by approximately 37%. FictionBook files are often distributed inside Zip archives, and most of hardware and software readers can work with compressed FictionBook files (*.fb2.zip) directly. The metadata and the plain text data are always placed in the beginning of the FictionBook file, while more heavyweight binary images are placed in the end. This allows software to start rendering or processing FictionBook before the file is available entirely.
FictionBook is the format of choice of some community-driven online electronic libraries. It does not allow for digital rights management of any kind.
The format is supported by e-book readers such as FBReader, AlReader, Haali Reader, STDU Viewer, CoolReader, Fly Reader, Okular, Ectaco jetBooks, Documents for iOS, and some others. Firefox can read FictionBook by installing an extension: FB2 Reader. Many hardware vendors support FictionBook in their firmware: BeBook One, BeBook Mini and BeBook Club in Europe (and other Hanlin V3 and V5 based devices), all PocketBook Readers, COOL-ER devices, Cybook Opus and Cybook Gen3, and ASUS Eee Reader DR900. Devices based on the Hanvon N516 design can read FictionBook if custom OpenInkpot firmware is installed; it is factory default for Azbooka 516. Amazon's Kindle, Barnes & Noble's Nook, and Sony devices do not support FictionBook directly.
Conversion to and from FictionBook2 (.fb2) files is possible via the cross-platform ebook management software Calibre. While conversion to, but not from, FictionBook2 format is available via Pandoc.