What is FB2 format?

FB2 (FictionBook 2) is an open XML-based ebook format developed in Russia. Unlike formats like EPUB that use compressed HTML, FB2 stores the entire book as a single structured XML document. This makes FB2 files easily editable with any text editor and ensures they remain readable even without specialized software.

The format was designed specifically for fiction and includes built-in support for book metadata (author, title, genre, annotation), structured content (chapters, sections, epigraphs, poems), footnotes and endnotes, and embedded images encoded as base64. FB2 is particularly popular in Russia, Ukraine, and other Eastern European countries, where many digital libraries offer books primarily in this format.

Tool description

This online FB2 reader allows you to open and read FictionBook files directly in your browser without installing any software. Simply upload your .fb2 or .fb2.zip file and start reading immediately. The tool parses the FB2 XML structure and renders it as formatted HTML with proper styling for all FB2-specific elements.

Features

  • Offline reading — once loaded, your book is available entirely in your browser with no server uploads
  • Compressed file support — reads both plain .fb2 files and compressed .fb2.zip archives
  • Full metadata display — shows book title, author, cover image, publisher, ISBN, and publication date
  • Table of contents — automatic chapter navigation extracted from the book structure
  • Rich formatting — proper rendering of epigraphs, poems, citations, footnotes, tables, and images

Supported elements

The reader correctly handles all standard FB2 elements:

Element type Rendering
Chapters and sections Hierarchical headings with navigation
Paragraphs Standard text paragraphs with proper spacing
Emphasis and strong Italic and bold text formatting
Epigraphs Styled blockquotes with author attribution
Poems and verses Preserved line breaks with indentation
Citations Blockquote styling with source attribution
Footnotes Superscript links to note sections
Images Embedded images decoded from base64
Tables Full table support with headers

How it works

When you upload an FB2 file, the reader performs these steps:

  1. Archive extraction — if the file is compressed (.fb2.zip), it's unzipped in memory using JSZip
  2. XML parsing — the FB2 content is parsed as XML to extract structure and data
  3. Metadata extraction — title, author, cover image, and other book information are read from the <title-info> and <publish-info> sections
  4. Image processing — binary images embedded in <binary> elements are converted to data URIs
  5. Content conversion — each <body> section is transformed into styled HTML while preserving the document hierarchy
  6. Chapter building — individual sections become navigable chapters with a generated table of contents

Use cases

  • Reading Russian ebooks — FB2 is the dominant format in Russian digital libraries, and this tool lets you read books without installing desktop software
  • Quick book preview — check the contents and formatting of FB2 files before converting them to other formats
  • Cross-platform reading — access your FB2 collection from any device with a web browser, including tablets and phones

Tips

  • For large books with many images, give the parser a few seconds to process all embedded graphics
  • Use the table of contents panel to jump between chapters quickly
  • The reader remembers your position within each chapter, so you can navigate away and return to where you left off
  • Zoom and font size settings are preserved between reading sessions

Limitations

  • DRM-protected FB2 files cannot be opened
  • Very large files (over 50 MB) may cause slow loading on older devices
  • Some non-standard FB2 extensions created by specific software may not render perfectly
  • EPUB Book Reader — for EPUB format ebooks
  • PDF Viewer — for PDF documents
  • Markdown Viewer — for Markdown files