EPUB Metadata Editor

View and edit EPUB ebook metadata: title, author, publisher, language, description. Edit Dublin Core fields in the OPF without breaking the book.

1.0.0
Version
Auth
Batch

About EPUB Metadata Editor

Calibre's metadata editor is the household tool for tweaking a single EPUB's title or author, but it ships as a 250 MB desktop install with a full ebook library system attached — overkill when all you need is to fix a typo in the title of one book before sending it to your reader. The hand-roll alternative is to unzip the EPUB, hunt for the .opf file, edit the right <dc:title> or <dc:creator> element, repack the ZIP with the mimetype entry uncompressed and first, then pray Apple Books or KOReader still accepts it.

This EPUB metadata editor does the surgical version — extract the current metadata to see what's in there, set new values for the 10 standard Dublin Core fields (title, creator, subject, description, publisher, contributor, date, language, rights, identifier), and download a fresh EPUB with the OPF rewritten correctly. Both EPUB 2 and EPUB 3 packages are supported. The mimetype entry is repacked as stored (uncompressed) and first, the container.xml layout is preserved, and only the metadata block in the OPF is touched — chapters, styles, images, fonts and the unique identifier stay byte-identical. A server-side whitelist on field names blocks arbitrary XML injection.

Use it to fix a typo before sending an EPUB to your Kindle, set a consistent author name across a series of self-published books, update the language tag so e-readers stop hyphenating English text as if it were German, change the publisher line after an imprint move, or rebrand a public-domain text for your own library. Files up to 50 MB are processed in a stateless serverless function and discarded immediately after the response.

EPUB Metadata Editor Use Cases

  • Self-publishers fixing a typo in a book title before resubmitting to KDP or Apple Books
  • Book bloggers normalising author names across a series for a clean library shelf
  • Librarians updating language tags so e-readers stop mis-hyphenating English text
  • Editors changing the publisher field after an imprint move or rebrand
  • Public-domain enthusiasts rebranding Project Gutenberg EPUBs for a personal library
  • Translators adding a contributor record for a translation edition
  • Quick-check workflows confirming what metadata a downloaded EPUB actually carries

EPUB Metadata Editor Features

  • Edit 10 Dublin Core fields — title, creator, subject, description, publisher, contributor, date, language, rights, identifier
  • Supports both EPUB 2 (.opf 2.0) and EPUB 3 (.opf 3.0) packages with their respective metadata namespaces
  • Multi-value fields handled correctly — multiple authors, multiple subjects, multiple contributors
  • Server-side whitelist on field names — hand-crafted JSON cannot inject arbitrary XML or DC namespace elements
  • Repacks the mimetype entry as stored (uncompressed) and first in the ZIP per the EPUB spec, so readers still accept the file
  • Only the OPF metadata block is rewritten — chapters, styles, images, fonts and unique-identifier structure stay byte-identical
  • Files up to 50 MB processed in a stateless serverless function and discarded immediately after the response

How to Use EPUB Metadata Editor

Upload your .epub file

Drag-and-drop or click to select an EPUB (up to 50 MB). Works on books from Apple Books, Kobo, KDP, Project Gutenberg, Standard Ebooks and any other source — the .opf format is the same.

Extract to see current metadata

Click Extract. The OPF metadata block is read and the 10 Dublin Core fields are shown in a table. The book's unique-identifier (often an ISBN or a UUID) is shown for reference but is not editable from the UI.

Edit the fields you want to change

Type new values into the fields. Leave any field blank or unchanged to keep the original value. For multi-author or multi-subject books, separate values with the multi-value control — they're written back as separate dc:creator or dc:subject elements.

Click Update

The EPUB is repacked with the new OPF metadata block, preserving every other resource byte-identical. The mimetype entry is written as stored (uncompressed) and first in the ZIP, which is what the EPUB validator checks for.

Download and verify

Download the rewritten .epub and open it in Calibre, epubcheck or your reader of choice to confirm the metadata changes landed. The book's table of contents, chapters and fonts will be identical to the original.

EPUB Metadata Editor FAQ

No. Only the OPF metadata block (the section between <metadata> and </metadata> in the package document) is rewritten. The chapter XHTML files, stylesheets, fonts, images, table of contents and spine order stay byte-identical to your upload. Re-running epubcheck on the result yields the same content validation as the original.

Yes. The parser handles both EPUB 2.0.1 (where DC fields live under the dc: namespace) and EPUB 3 (where the same DC fields use dcterms and meta refinements). The output EPUB keeps whichever version your input declared — a 2.0.1 book stays 2.0.1, a 3.0 book stays 3.0, with the metadata block written in that version's idiomatic style.

Yes. Each of dc:creator, dc:contributor and dc:subject supports multiple values. Enter them as a JSON array via the multi-value control and they're written back as separate XML elements in the OPF, which is the spec-correct way (rather than concatenating with a comma into a single dc:creator).

Calibre is a full ebook library application with a metadata editor among many features — great if you manage a library, overkill for a one-off edit. Sigil is a full WYSIWYG EPUB editor. This tool does only the metadata subset, runs in the browser, takes 10 seconds end-to-end, and doesn't ask you to install anything. Use it when the task is 'fix author name on this one EPUB' and graduate to Calibre when you're organising a shelf.

Yes, provided the input passed. The mimetype entry is rewritten as uncompressed (stored) and placed first in the ZIP per the OCF spec — the two most common reasons homemade EPUBs fail epubcheck. The container.xml layout and OPF structural elements (manifest, spine, guide) are preserved; only the metadata block is touched. Re-running epubcheck on the output should produce the same outcome.

Because the unique-identifier (usually an ISBN, UUID or URN) is referenced from the package element via unique-identifier and is part of the EPUB's stable addressing — changing it can break Kobo, Apple Books and Calibre's deduplication. The dc:identifier value is shown for reference. If you need to set a fresh identifier (e.g. registering a new ISBN), use Sigil's metadata editor which rewrites the cross-reference too.

The EPUB is uploaded to a stateless serverless function (EPUB packaging needs a real ZIP pipeline) and deleted immediately after the response. Nothing is logged to durable storage. For DRM-protected files, this tool will refuse to repackage them (the spec doesn't allow it) — strip the DRM with the appropriate tool first if you're the rights holder.

Drop your .epub file here or click to upload

EPUB ebooks only • Max 50MB

EPUB Metadata Editor Tutorial

Why edit EPUB metadata?

EPUB files store all their bibliographic data in an OPF (Open Packaging Format) file inside the zip. This is what shows up in your e-reader as title, author, and publisher.

  • Fix scanned books: Free EPUBs from Project Gutenberg or Calibre often have wrong or incomplete metadata
  • Self-published authors: Update title, author name, ISBN before uploading to retailers
  • Library organization: Make your e-reader sort books correctly by author
  • Translation/edition info: Edit language, publisher, date

How does it work?

An .epub is a ZIP file with a META-INF/container.xml pointing to the main .opf package file. The OPF contains a <metadata> block with Dublin Core fields. This tool finds the OPF, edits only the metadata block, and rebuilds the .epub. Book content (chapters, images, fonts) is preserved verbatim.

Editable fields (Dublin Core)

  • title — Book title
  • creator — Author(s); separate multiple with line breaks
  • contributor — Translator, illustrator, etc.
  • publisher — Publishing house
  • date — Publication date (e.g. 2023 or 2023-05-12)
  • language — ISO 639 code (en, zh, ja)
  • subject — Genre/category tags
  • description — Synopsis or blurb
  • rights — Copyright statement
  • identifier — ISBN, UUID, etc.

EPUB 2 and EPUB 3 are both supported. The unique identifier (book ID) is preserved automatically. For multi-value fields like author or subject, separate entries with new lines.