Free EPUB Metadata & Cover Editor

Worked example

Press "Try a sample". The file chip shows untitled_document_final (2).epub with "EPUB 3". The form is filled with Title "untitled_document_final (2)", Authors "Unknown" and Language "en", and the cover panel says "This book has no cover". The checkbox reads Name the file "Unknown - untitled_document_final (2).epub". Type "The Lighthouse Keeper" as Title, "Mira Okafor" as Authors, "Harbour Lights" as Series, 1 as "Number in series" and "sea, fiction" as Tags. The checkbox now reads Name the file "Mira Okafor - The Lighthouse Keeper.epub". Press "Add a cover" and pick a 3000 × 4500 picture: the panel shows 1600×2400 and a size, with a "Keep the old one" link. Press "Save EPUB". The file downloads, and the page says "Saved as Mira Okafor - The Lighthouse Keeper.epub."

Which settings to use, and the limits

• Fix the title and author first. "Authors" takes one name per line, and a semicolon also starts a new name. A single line that contains "&" or "and", such as "Ann Lee & Bo Chen", is split into two authors; "Last, First" is kept whole. Only authors are replaced: as the page says, editors, translators and illustrators already in the book are kept. The checkbox Name the file "Author - Title.epub" is ticked by default and uses the first author. Characters that are not allowed in file names become spaces, the title is cut to 120 characters and the author to 60. Untick it to keep the original file name.
• Add a series so the book sorts with its set. Type the name in "Series" and the position in "Number in series". The tool writes the calibre series fields and, for an EPUB 3 book, the standard EPUB 3 series entry as well. A number such as 1.0 from calibre is shown as 1. The number is only written when a series name is present. If you empty "Series", the series entries are removed from the book. Existing calibre series fields and EPUB 3 series entries are read when you open the file.
• Use a language code, not the language's name. "Language" suggests 34 codes, including en, pt-BR, zh-Hans and zh-Hant. The box accepts two or three letters, optionally followed by parts such as -BR. If you type English or en_US, the hint turns amber and says "Use a language code such as en, fr or pt-BR, not the language's name." The warning does not block saving. If the box is empty, the tool still writes en, because the page notes that Kindle needs a language. So check this box on books that are not in English.
• Add or replace the cover. The button reads "Add a cover" or "Replace cover" and opens a picker for JPEG, PNG, WebP, GIF, AVIF and BMP pictures. A picture larger than 1600 × 2560 is scaled down to fit and a smaller one is not enlarged. The new cover is saved as PNG if the old cover was a PNG, and otherwise as JPEG at 90 percent quality on a white background. The panel shows its size and a "Keep the old one" link. A cover of the same format replaces the old file in place; a different format is added as a new file and the old one stops being the cover.
• Expect everything you did not edit to stay as it was. The package file is edited as text, so identifiers, rights, vendor entries, comments and other roles are left alone, and the chapters are not touched. The exceptions are cover pages that showed the old picture, which are pointed at the new one, and the title in the older table-of-contents file, which is updated. EPUB 3 books also get a new modified time. The saved file starts with the uncompressed mimetype entry and the rest is compressed. The chip shows "EPUB 2" or "EPUB 3".
• Keep tags, date and description as plain text. "Tags (comma-separated)" is split on commas, semicolons and line breaks, and each tag is saved as a subject. "Published" is written as typed, with 2024-05-01 as the example in the box. "Description" and "Publisher" are plain text. A field you leave empty is removed from the book, except Language, which falls back to en. The whole file is read into memory, and nothing is uploaded. After saving, the page says to send the EPUB with Send to Kindle (the app, the website or email) to see the new title, author and cover on a Kindle.

Common problems and how to fix them

It says "This file is not an EPUB (it could not be opened as one). If it is a MOBI or AZW3 book, convert it with MOBI to EPUB first."

An EPUB is a ZIP archive, and the file could not be opened as one. A MOBI or AZW3 book renamed to .epub, or a download that was cut short, fails this way, and so does any unexpected error while opening. For Kindle formats use the "MOBI to EPUB Converter"; otherwise download the original again.

It says "This book is protected with DRM, so it cannot be edited."

The book's encryption list names something other than the two font-scrambling methods, so the tool treats it as copy-protected and stops before reading the metadata. Font scrambling alone is not DRM and does not trigger this. The tool does not remove protection. Use a copy of the book that came without DRM.

It says "This EPUB is damaged: its table of contents file (container.xml) is missing."

The tool looks for META-INF/container.xml at the top of the archive, and that file names the book's package file. It is missing, or the book's files sit inside an extra folder. A second message says "This EPUB is damaged: its package file (OPF) is missing." when container.xml points to a file that is not there. Re-export the book from the program that made it, or download it again.

It says "That picture could not be opened. Try a JPG or PNG."

Your browser could not decode the picture, or could not encode the resized cover. The picker lists JPEG, PNG, WebP, GIF, AVIF and BMP, but a damaged file or a format your browser cannot read still fails. The book itself is unchanged and no cover is set. Open the picture in an image editor, save it as JPG or PNG, and choose it again.

It says "The EPUB could not be saved. Please try again."

Something failed while the book was being rebuilt, and the tool shows this one message for every cause. The whole book is held in memory while it is read, edited and compressed again, so a very large book can fail on a device with little memory. Press "Save EPUB" again, remove a large new cover with "Keep the old one", or try a desktop computer.

How it compares

This tool changes the descriptive fields and the cover of one EPUB: title, authors, series, language, publisher, published date, tags, description and cover. It does not convert formats, remove DRM, edit chapters or the table of contents, or change identifiers. A desktop library manager can edit more fields, work on many books at once and keep a library; this tool opens one book at a time. Because only the fields on the form are rewritten and everything else is copied as it was, a book that opened before should still open afterwards. In exchange nothing needs installing, and the file is edited in your browser and not uploaded.