About FB2 Files

FictionBook

Released 2004 By Dmitry Gribov & FictionBook community (Russia)

FictionBook (FB2) is an XML-based eBook format popular in Russia and Eastern Europe. It provides structured semantic markup for fiction and non-fiction books.

Family

eBooks

Extension

.fb2

MIME Type

application/x-fictionbook+xml

Can Use As

Input

The story

HOW FB2
CAME TO BE.

FictionBook (FB2) is the Russian-speaking world’s answer to EPUB. Created in 2004 by Dmitry Gribov and a community of Russian developers and librarians, FB2 is an XML-based ebook format explicitly designed for fiction: one file holds the entire book as pure semantic markup (sections, paragraphs, italics, poems), with no CSS or visual styling. Readers apply their own typography, which makes FB2 refreshingly simple and radically portable.

FB2 became the dominant format of the largest Russian ebook sites (Flibusta, Lib.rus.ec, LitRes) and the preferred input for Russian e-readers (PocketBook, ONYX). Outside the Russian-speaking world FB2 is rare, but the format is technically superior to MOBI for text-only books — XML structure means perfect text extraction, search, and reflow on any screen.

CURIOSITIES &
TRIVIA.

FB2 is essentially "EPUB without CSS" — semantic XML only, no visual styling.

The format dominates Russian-language ebook distribution through sites like Flibusta and LitRes.

FB2 files can contain Base64-encoded cover images and illustrations inline — no external assets.

The spec is maintained by a grassroots community, not a standards body — and has remained backward-compatible for 20 years.

PocketBook e-readers, popular in Eastern Europe, default to FB2 rather than EPUB.

STRENGTHS &
LIMITATIONS.

Strengths

Pure XML — trivial to parse, search, and transform.
Single-file ebooks with inline images.
Excellent on low-powered e-readers.
De-facto standard in Russian-language ebook ecosystem.
Simple structure makes conversion to any other format straightforward.

Limitations

No styling, no custom fonts, no fixed layouts.
Minimal Western-language tooling.
Kindle and Apple Books do not support FB2 natively.
Non-fiction with complex typography (textbooks, cookbooks) is a poor fit.

Typical Sizes & Weights

Novel (text only)

200-800 KB

Novel with cover image

300 KB - 1.5 MB

Illustrated children's book

5-30 MB

Technical Specifications

MIME type: application/x-fictionbook+xml
Extensions: .fb2, .fb2.zip
Container: Single XML file (optionally zipped)
Standard: FictionBook community spec (maintained on GitHub)
Encoding: UTF-8 (required)

CONVERT FROM
FB2

fb2 pdf fb2 docx fb2 odt fb2 txt fb2 md fb2 html fb2 epub fb2 mobi fb2 azw3 fb2 rst fb2 htmlz fb2 txtz fb2 pdb

CONVERT TO
FB2

epub fb2 mobi fb2 azw3 fb2 htmlz fb2 txtz fb2 pdb fb2 lrf fb2 snb fb2 lit fb2 cbz fb2 cbr fb2

Common Use Cases

Russian-language eBooks, Eastern European digital libraries.