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EPUB & Ebook Viewers

Understanding EPUB Files

EPUB (Electronic Publication) is the open standard format for ebooks. Unlike PDF, EPUB content is reflowable—text adapts to different screen sizes and font preferences. An EPUB is essentially a ZIP archive containing XHTML, CSS, images, and metadata files structured according to specifications.

EPUB Structure

Every EPUB contains several key components: the OPF (Open Packaging Format) file stores metadata like title, author, and ISBN; the NCX or navigation document defines the table of contents; content files contain the actual book text in XHTML; and the manifest lists all files included in the ebook.

Metadata Inspection

Our viewer extracts complete metadata from EPUB files including bibliographic information (title, author, publisher, ISBN), technical details (language, unique identifier, publication date), and structural information (word count, chapter count, file composition). This is useful for publishers managing catalogs, librarians organizing collections, and authors verifying exported files.

Privacy and Compatibility

All EPUB processing happens in your browser using JSZip to parse the archive. Your ebook files never leave your device. The viewer supports both EPUB 2 (using NCX navigation) and EPUB 3 (using HTML5 nav elements) formats.

Use Cases

  • Publishers: Verify metadata before distribution, check file structure for errors
  • Librarians: Catalog books, extract ISBN and bibliographic data
  • Authors: Preview exported ebooks, verify TOC and metadata
  • Developers: Debug EPUB generation, inspect file structure

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