EPUB Metadata Editor fixes the information an ebook carries about itself, the details that decide how it appears and sorts in Calibre, Apple Books, Kobo, Google Play Books and other library apps. Open an EPUB and every field is filled in from the book: title, authors (one per line), language, publisher, publication date, ISBN, tags, series name and number, and description. Change what you need, replace or add a cover image, and save. The tool rewrites only the package metadata and the cover, and packages a new EPUB with the same chapters, styles and images, so nothing else in the book changes. Series information is written both the way Calibre and most readers expect and in the official EPUB 3 form, and the modified date is updated so readers notice the change. The book’s internal identifier is deliberately kept, because some books use it to unlock their embedded fonts. Everything runs in your browser, so the book is never uploaded. When you are making a new book rather than fixing one, start with Create EPUB. To check the result, open it in EPUB Reader, and to make a printable copy use EPUB to PDF Converter.
Ebook metadata lives in a single XML file inside the EPUB, the package document, usually named content.opf. Its metadata section uses Dublin Core elements, a long established standard for describing documents: dc:title, dc:creator for authors, dc:language, dc:publisher, dc:date, dc:description, dc:subject for tags, and dc:identifier for identifiers such as the ISBN. EPUB 3 adds meta elements that refine these, for example marking a creator’s role as author with the MARC relator code aut, or attaching a series position to a collection. Library apps read this file when you import a book, so the values here decide how the book is listed, sorted and grouped. A few details are easy to get wrong when editing by hand. Every EPUB 3 book must carry exactly one dcterms:modified timestamp, which this editor updates on save. The language must be a valid language code, such as en, sr or de, because readers use it for hyphenation and text to speech. Series support has two competing conventions: Calibre’s calibre:series and calibre:series_index meta tags, understood by Calibre and most Android and e-ink readers, and the EPUB 3 belongs-to-collection property with a group-position, used by Apple Books. Writing both keeps the series visible everywhere. Finally, the EPUB must be repackaged with an uncompressed mimetype file first in the archive, or some readers refuse to open it, which the editor handles automatically.