Format at a glance
- Full name
- Electronic Publication
- File extensions
- .epub
- MIME types
- application/epub+zip
- Category
- E-books
- Compression
- ZIP-based container
- Transparency
- Not applicable
- Animation
- Not applicable
- Properties
- Reflowable layout
Suitable tools
What is this format?
An EPUB file contains XHTML or HTML content, CSS, images, a package document and navigation information. The files follow a defined directory and manifest structure inside a ZIP-compatible archive.
EPUB can be reflowable or fixed-layout. Digital rights management is external to the core file structure and may prevent ordinary tools from reading protected books.
What is it used for?
- Novels and long-form e-books
- Technical books with structured chapters
- Accessible publications with adjustable text
- Offline reading across dedicated e-readers and apps
Which programs can open it?
- Apple Books and Google Play Books
- Calibre and Thorium Reader
- Kobo and compatible e-readers
- Foliate and other EPUB readers on Linux
Support across devices and browsers
Calibre, Thorium and other e-book readers open unprotected EPUB files.
Apple Books and third-party readers support EPUB.
Calibre, Foliate and compatible readers support EPUB.
Google Play Books, Kobo and many reader apps open EPUB.
Apple Books opens EPUB natively.
Browsers need a reader application or JavaScript EPUB viewer; EPUB is not a normal standalone web page.
Advantages
- Text can reflow to different screens and font sizes
- Open standard based on familiar web technologies
- Can package chapters, navigation, images and metadata in one file
Disadvantages
- Layout may differ between reading systems
- DRM-protected books cannot be processed like ordinary EPUB files
- Complex scripts, fonts and fixed layouts are not rendered identically everywhere
Comparison with alternatives
EPUB usually reflows for reading; PDF preserves fixed page geometry.
EPUB packages multiple HTML resources, navigation and metadata for offline publication.
FB2 is an XML-based book format; EPUB has broader commercial reader and publishing support.
LocalFileLab support
LocalFileLab extracts readable chapter documents from unprotected EPUB archives.
It can generate a basic EPUB from supported text and document content.
EPUB can be repackaged as an archive, but this is not semantic e-book optimization.
There is no full e-reader preview; extracted or converted content can be inspected after processing.
Generated EPUB includes basic title and language data; rich publication metadata is not fully preserved.
Related formats
Frequently asked questions
Can I open EPUB directly in a browser?
Not as a normal page. A browser extension or EPUB reader must unpack the publication and display its spine and navigation.
Why does an EPUB look different in two apps?
Reflowable books adapt to fonts, screen size and reader styles, and CSS support varies between reading systems.
Can LocalFileLab open DRM-protected EPUB files?
No. The local extraction path is intended for readable, unencrypted publication files and does not remove DRM.