.epub file format
View, preview, inspect, and learn how EPUB files are used for ebooks, digital publishing, documentation, manuals, reading workflows, and content distribution.
Also known as: Ebook, E-book
Format
.epub
Original files stay unchanged. Tools download a new file when output is generated.
Every tool listed here works with .epub files and runs in your browser. If the task you need is not here, the related formats below may cover it.
Unzip an .epub and you find XHTML documents for the chapters, CSS for styling, images, and a package file — usually content.opf — that lists everything, records the metadata, and defines the reading order. There is also a navigation document providing the table of contents. Knowing this is why an EPUB can be inspected in a browser: the content is already HTML.
EPUB text reflows to fit the screen and the reader's chosen font size, which is what makes it comfortable on a phone or e-reader where a fixed-layout PDF is not. The trade-off is that page numbers are not stable — there is no fixed page in a reflowable book, which is why citing an EPUB by page does not work.
Title, author, language, identifier, and publication date are recorded in content.opf rather than inferred from the filename. So is the cover: it is a normal image in the archive, marked as the cover by a metadata reference. A book showing the wrong title or no cover art in a library app is almost always a metadata problem rather than a corrupt file.
Kindle devices do not read EPUB natively, but Amazon's Send to Kindle accepts EPUB files and converts them on the way in — and has since retiring MOBI in 2022. So an EPUB will reach a Kindle, just not as an EPUB. Expect conversion to alter fine typographic control.
Yes, by sending it through Send to Kindle, which converts the file. Kindle hardware does not open EPUB directly, and conversion can change layout and typography.
Both come from the metadata in the package file, not the filename. If they are wrong there, every reading app will show them wrong.
EPUB reflows text to the screen and font size, which suits small displays. PDF preserves an exact fixed layout, which suits print and anything where page numbers must be stable.
Yes — the chapters are XHTML inside the archive, so the text is directly accessible without any conversion step.