Question 1

What is an FB2 file?

Accepted Answer

FB2 (FictionBook 2.0) is an open XML-based ebook format popular in Russia and Eastern Europe. Unlike EPUB (which is a ZIP of XHTML files), FB2 is a single XML file containing the entire book — metadata (title, author, genre, lang), description, body with sections, and optional footnotes / epigraphs. The format is human-readable with any text editor.

Question 2

How does this reader work?

Accepted Answer

We parse the FB2 XML using the browser's native DOMParser, then walk the XML tree to extract: (1) the block (title-info with book title, authors, genre, lang, annotation), (2) the element with its nested

structure (chapters), (3) optional for footnotes. We render the book text as clean HTML with proper typography (em-dashes, quotation marks, paragraph indentation).

Question 3

Are all FB2 features supported?

Accepted Answer

Most. We support: , <author>, <genre>, <lang>, <annotation>, <body> with <section> nesting, <p> paragraphs, <emphasis>, <strong>, <strikethrough>, <code>, <sub>/<sup>, <image> (with inline base64 or references to binary elements), <poem>/<stanza>/<v> for verse, <epigraph>, <cite>, <table>, <a> links, and <empty-line>. We strip <stylesheet> and inline CSS for safety. Custom XSL transformations are not supported.

Question 4

Can I read .fb2.zip files?

Accepted Answer

Not directly — .fb2.zip is a ZIP archive containing one or more FB2 files. Use our ZIP Extractor tool to unzip the archive first, then open the extracted .fb2 file here. Some libraries distribute books as .fb2.zip to save space (FB2 is plain XML and compresses well — typically 70-80% reduction).

Question 5

Can I convert FB2 to EPUB?

Accepted Answer

Not directly with this tool — it's a reader only. For conversion, use Calibre (desktop app). The FB2 format is well-supported by Calibre's conversion engine and produces high-quality EPUBs. We focus on reading rather than converting to keep the bundle size small.

Question 6

What extra features does this tool have compared to others?

Accepted Answer

10 extras: (1) Drag-drop file input. (2) Font size adjustment (5 levels: sm to 2xl). (3) Dark / light reading mode. (4) Bookmark chapter (localStorage — resume from last chapter on reopen). (5) Search within book text with result jumping. (6) Copy chapter text to clipboard. (7) File info panel — title, author(s), genre, lang, file size. (8) Chapter list / table of contents (sidebar). (9) Reading progress percentage (chapters read / total). (10) History of recently opened books (localStorage — last 10).

Question 7

Is my book uploaded anywhere?

Accepted Answer

No. The FB2 XML is parsed entirely in your browser using DOMParser. Book contents never leave your device. Only book titles + author names are saved to localStorage for the resume feature.

Question 8

What about FB3 (FictionBook 3)?

Accepted Answer

FB3 is a newer ZIP-based format that's largely unused outside a few Russian e-readers. We don't support it. If you have an FB3 file, convert it to FB2 or EPUB with Calibre first.

FB2 Reader

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