FreeDeskTools

EPUB Metadata & Privacy Editor

Last Updated: June 28, 2026

100% Client-Side Processing

Your EPUB files never leave your browser. All metadata editing happens in memory, locally.

✓ Browser Processing ✓ Zero Uploads ✓ EPUB Metadata Editing
EPUB Metadata & Privacy Editor

Drop your EPUB file here

or click to browse. Supports EPUB format only.

EPUB Metadata & Privacy Editor

Upload an EPUB file to inspect, edit, or remove metadata. Your e-book content never leaves your browser.

Privacy Audit & Trust Verification

This tool operates entirely in your browser. No EPUB data is transmitted, stored, or logged. All processing uses volatile memory buffers that are released on tab close.

Processing Location: Browser Books Uploaded: 0 Server Requests: 0 Metadata Edited: — Book Content Modified: No Validation Passed: — Privacy Protected: —

Inspect and edit EPUB metadata without uploading your books. Supports Privacy Cleanup, Selective Editing, and Anonymization modes. Preserves chapters, images, CSS, fonts, and navigation. 100% browser-based.

100% Browser Processing
Zero Uploads
EPUB Validation
Metadata Editing
Offline Compatible
No Login
Privacy First
Content Preserved

How To Use

Follow these simple steps to get started with epub metadata & privacy editor.

1

Upload your EPUB

Drag and drop an EPUB file or click to browse. The tool extracts and parses the OPF package document to display all embedded metadata.

2

Inspect metadata and privacy risks

Review the Metadata Inspector table showing all fields, values, and risk levels. The Privacy Dashboard displays your privacy score and highlights personal identifiers, custom fields, and tracking fields.

3

Choose sanitization mode

Select Privacy Cleanup to remove identifiers and tracking fields, Selective Editing to choose individual fields, or Anonymization to replace identities with anonymous placeholders.

4

Download sanitized EPUB

Click 'Sanitize & Download' to get your clean EPUB with validated structure and zero content modification.

Real-World Examples

Practical situations where epub metadata & privacy editor helps solve real problems.

Author Privacy Protection

Remove personal identifiers, author names, and publisher information from EPUB files before sharing manuscripts, preprints, or reviews with editors and readers.

Publisher Asset Sanitization

Clean publisher-specific identifiers, internal IDs, tracking metadata, and Calibre/Sigil custom tags from EPUB files before distribution to retailers or reviewers.

Academic Research Privacy

Remove all personal metadata, institutional identifiers, and tracking watermarks from research publications, dissertations, and academic manuscripts before sharing with collaborators.

Why Use This Tool

Discover how this tool can improve your workflow and productivity.

100% Browser Processing

Your EPUB files never leave your device. All ZIP extraction, OPF XML parsing, metadata editing, and EPUB rebuilding happens locally via Web Workers.

Full OPF Metadata Parser

Comprehensive EPUB metadata parser that reads every field from the OPF package document — title, creator, publisher, identifier, UUID, ISBN, language, rights, subjects, dates, and custom metadata.

Three Sanitization Modes

Privacy Cleanup removes identifiers and tracking fields. Selective Editing lets you choose individual fields. Anonymization replaces identities with anonymous placeholders.

Content Integrity Preserved

Only the OPF metadata XML is modified. Book content — XHTML, CSS, fonts, images, SVG, navigation, TOC, hyperlinks, footnotes — remains 100% unchanged.

Common Use Cases

Practical scenarios where this tool can help you get things done.

Author Privacy Protection

Remove personal identifiers, author names, and publisher information from EPUB files before sharing manuscripts, preprints, or reviews with editors and readers.

Publisher Asset Sanitization

Clean publisher-specific identifiers, internal IDs, tracking metadata, and Calibre/Sigil custom tags from EPUB files before distribution to retailers or reviewers.

Academic Research Privacy

Remove all personal metadata, institutional identifiers, and tracking watermarks from research publications, dissertations, and academic manuscripts before sharing with collaborators.

Tool Summary

Quick facts about this tool at a glance.

Purpose Inspect, edit, and sanitize EPUB metadata while preserving all book content, formatting, and navigation.
Best For Authors, publishers, researchers, journalists, students, editors, self-publishing writers, librarians, privacy-conscious readers, and anyone sharing EPUB files who needs to protect personal metadata.
Processing 100% browser-side via Web Worker using JSZip for EPUB ZIP extraction and DOMParser/SimpleXmlDoc for OPF XML parsing.
Cost Free.
Sign-Up Required No.
Data Storage Volatile browser memory. EPUB files are released on tab close.

What Is EPUB Metadata & Privacy Editor?

An EPUB Metadata & Privacy Editor is a browser-based privacy tool that parses, inspects, and sanitizes metadata from EPUB files using client-side ZIP and XML processing — all without uploading books, with zero content modification, and with full EPUB structure validation.

About This Tool

How EPUB Files Work

EPUB (Electronic Publication) is the standard format for digital books supported by almost all e-readers, tablets, and phones. Despite its .epub extension, an EPUB file is fundamentally a ZIP archive containing structured XHTML content, CSS stylesheets, images, fonts, and an XML-based metadata system.

EPUB Package Structure

Every EPUB file follows a strict directory structure:

1. mimetype — A plain text file (uncompressed in the ZIP) containing 'application/epub+zip' that identifies the file format 2. META-INF/ — Directory containing container.xml, which points to the OPF package document 3. OEBPS/ or content/ — The main content directory containing: - package.opf — The OPF (Open Packaging Format) file with all metadata, manifest item references, and spine reading order - XHTML files — Individual chapters and content sections - CSS files — Stylesheets controlling typography and layout - Images — Cover art, illustrations, and embedded graphics - Fonts — Embedded font files for custom typography - nav.xhtml — The EPUB 3 navigation document - toc.ncx — The EPUB 2 table of contents (for backward compatibility)

OPF Metadata Explained

The OPF package document (package.opf) is the heart of EPUB metadata. Its <metadata> element contains both standard Dublin Core elements and OPF-specific properties:

Dublin Core Elements

  • dc:title — The book's title (may include subtitle)
  • dc:creator — The primary author or creator
  • dc:contributor — Additional contributors, editors, illustrators, translators
  • dc:publisher — The publishing entity
  • dc:description — Synopsis or description of the book
  • dc:language — Language code (e.g., en, fr, es)
  • dc:identifier — Unique identifier (ISBN, UUID, publisher ID, URL)
  • dc:date — Publication date
  • dc:source — Source from which this ebook was derived
  • dc:coverage — Spatial or temporal coverage of the content
  • dc:relation — Related works
  • dc:type — Nature or genre of the content
  • dc:rights — Copyright and license information
  • dc:subject — Subject categories and keywords
  • dc:format — File format of the ebook

OPF Properties

  • meta elements with name/content attributes for Calibre IDs, Sigil metadata, series information, cover references, and custom application data
  • meta elements with property/refines attributes (EPUB 3) for enhanced metadata like identifier types, source URLs, and modified dates

Privacy in Digital Books

EPUB metadata can reveal significant personal information. When you purchase or download an ebook, your copy may contain unique identifiers that could theoretically be used to trace the book back to you. Authors sharing manuscripts may inadvertently expose their identity through Calibre, Sigil, or publishing software metadata.

Identifiers: ISBN vs UUID

ISBN (International Standard Book Number) is a global identifier for published books. It identifies the edition and format but not individual copies. UUID (Universally Unique Identifier) is a 128-bit identifier that can be randomly generated. Some publishers use UUIDs to track specific copies. Privacy Cleanup mode removes both, while preserving the book's bibliographic information.

Custom Metadata and Tracking Watermarks

Publishing and ebook management software commonly embeds custom metadata:

  • Calibre: book IDs, library identifiers, author sort order, timestamps
  • Sigil: generator version, unique identifiers
  • Adobe Digital Editions: vendor-specific tags
  • Apple Books: custom namespace metadata
  • Kobo: vendor-specific identifiers

These fields can reveal which software was used to create or manage the book, potentially exposing the author's tools and workflow.

Differences Between Content and Metadata

Understanding this distinction is critical: Metadata is NOT content. The metadata in the OPF file describes the book but is separate from the book itself. Content files (XHTML chapters, CSS, fonts, images) contain the actual readable material. The EPUB Metadata & Privacy Editor only modifies metadata XML — your book's text, layout, styling, and images remain completely untouched.

Browser-Based EPUB Metadata Editing

Editing EPUB metadata in the browser requires several steps, all executed locally:

1. ZIP Extraction: JSZip reads the EPUB's ZIP structure in memory

2. OPF Location: META-INF/container.xml tells the parser where to find the OPF file 3. XML Parsing: The OPF metadata element is parsed to extract all Dublin Core and OPF properties 4. Metadata Editing: Based on the selected mode, specific metadata fields are modified or removed 5. EPUB Rebuilding: The modified OPF is written back, and the EPUB is re-zipped with the same directory structure 6. Validation: The rebuilt EPUB is validated for structure and integrity

How to Protect Author Privacy

For authors, researchers, and publishers sharing EPUB files, consider these best practices:

1. Remove personal identifiers: Strip Calibre IDs, Sigil identifiers, and custom UUIDs before sharing 2. Use Anonymization: Replace author and publisher info with anonymous placeholders for blind reviews 3. Verify before distribution: Always validate the EPUB after metadata editing to ensure integrity 4. Check for watermarks: Use the Watermark Inspector to detect hidden tracking fields 5. Avoid cloud services: Use browser-based tools that process files locally to prevent metadata leakage through uploads

EPUB Preservation Guarantee

When editing EPUB metadata, the following are never modified:

  • XHTML chapter files (the book text)
  • CSS stylesheets (typography and layout)
  • Embedded fonts
  • Images and cover art
  • SVG graphics
  • Navigation documents (nav.xhtml, toc.ncx)
  • Hyperlinks and cross-references
  • Footnotes and endnotes
  • Reading order (spine)

The only file modified is the OPF package document's metadata section.

Quick Summary

Enterprise-grade EPUB metadata inspection and sanitization entirely in the browser. Uses JSZip to extract the EPUB archive, locate the OPF package document via META-INF/container.xml, and parse the complete metadata block including Dublin Core elements (title, creator, contributor, publisher, description, language, identifier, date, source, coverage, relation, type, rights, subject, format) and OPF 2.0/3.x properties (meta elements with name, content, property, refines attributes). Supports three sanitization modes: Privacy Cleanup (remove identifiers, UUIDs, custom IDs, personal metadata, unknown fields, and tracking fields), Selective Editing (per-field checkboxes with custom replacement values), and Anonymization (replace author with Anonymous, publisher with Unknown Publisher, identifier with generic UUID). Watermark Inspector detects Calibre custom metadata, Adobe identifiers, vendor-specific fields, unknown XML namespaces, and suspicious metadata. Privacy Dashboard with animated cards showing metadata count, personal identifiers, custom fields, tracking fields, watermark count, and privacy score (0-100). Includes EPUB structure validation (ZIP integrity, mimetype, container.xml, OPF references, manifest, spine, XML syntax). Processing report with JSON/CSV export, session metrics dashboard, and localStorage preference persistence. Content files (XHTML, CSS, fonts, images, SVG, navigation, TOC, footnotes) are never modified. DRM detection with clear warning — does not remove or bypass DRM.

Related Concepts

Explore related terms and topics associated with epub metadata & privacy editor.

clean epub metadata client sideremove personal identifiers from ebooksanitize epub file online freeepub metadata editor secureedit epub metadata locally

Frequently Asked Questions

Common questions about epub metadata & privacy editor.

How do I remove metadata from an EPUB file?

Upload your EPUB file to the EPUB Metadata & Privacy Editor. The tool automatically extracts and displays all metadata from the OPF package document. Select Privacy Cleanup mode to remove identifiers, UUIDs, custom metadata, and tracking fields. Click 'Privacy Cleanup & Download' to get your sanitized EPUB — all processed locally in your browser.

Are my EPUB files uploaded to any server?

No. All processing — ZIP extraction, OPF XML parsing, metadata editing, and EPUB rebuilding — happens entirely in your browser using Web Workers and JSZip. Your EPUB files never leave your device. No uploads, no servers, no third-party access.

Can this tool remove DRM from EPUB files?

No. This tool does not remove or bypass DRM (Digital Rights Management). If a DRM-protected EPUB is detected, the tool displays a warning and disables metadata editing. You can only edit metadata on unprotected EPUB files.

Can I remove author or publisher information?

Yes. The Anonymization mode replaces author names with 'Anonymous' and publisher information with 'Unknown Publisher'. The Selective Editing mode lets you choose individual fields including creator, publisher, contributor, and rights. Privacy Cleanup mode strips personal identifiers while leaving author and publisher fields intact.

Will the EPUB formatting or content change?

No. Only the OPF metadata XML is modified. The book content — XHTML chapters, CSS stylesheets, embedded fonts, images, SVG graphics, hyperlinks, table of contents, navigation, and footnotes — remains 100% unchanged. The EPUB maintains its original formatting, layout, and reading experience.

What is EPUB metadata?

EPUB metadata is structured information embedded in the OPF (Open Packaging Format) package document within every EPUB file. It describes the book's properties including title, author, publisher, language, ISBN, UUID, subjects, rights, dates, and custom metadata. Unlike content files (XHTML, CSS, images), metadata is stored in XML format and can be safely edited without affecting the book's content.

What identifiers are typically embedded in EPUB files?

EPUB files commonly contain multiple identifiers including ISBN (International Standard Book Number), UUID (Universally Unique Identifier) generated by publishing software, publisher-specific IDs, Calibre book IDs, Sigil identifiers, DOI (Digital Object Identifier), and custom internal identifiers. These can reveal the publisher, distributor, or specific edition of a book.

Can I edit ISBN fields in an EPUB?

Yes. The Metadata Inspector displays all identifiers including ISBN, UUID, Calibre IDs, and custom identifiers. The Selective Editing mode allows you to edit or clear individual identifier fields. Note that while you can remove an ISBN from the metadata, this does not affect any ISBN printed on the book's cover image or embedded in content files.

What is the difference between content and metadata in EPUB?

Content refers to the actual book text stored in XHTML files, along with CSS for styling, images, fonts, and SVG graphics. Metadata is descriptive information stored in the OPF XML file, including title, author, publisher, and identifiers. The EPUB Metadata & Privacy Editor only modifies metadata XML — content files are never touched, ensuring the book reads exactly as published.

How does browser-based EPUB editing work?

The tool uses the JSZip library running in a Web Worker to extract the EPUB (which is a ZIP archive) entirely in your browser's memory. It locates the OPF package document via META-INF/container.xml, parses the metadata XML, presents it for inspection and editing, modifies only the selected metadata, and rebuilds the EPUB — all without any data leaving your device.

Can Calibre or Sigil metadata be detected and removed?

Yes. The tool includes a Watermark Inspector that specifically detects Calibre custom metadata, Sigil identifiers, Adobe vendor fields, vendor-specific XML namespaces, and other application-specific metadata. All detected vendor metadata can be removed through Privacy Cleanup mode or individually through Selective Editing.

How can I verify which metadata my EPUB contains?

Upload the EPUB to the Metadata Inspector. The tool immediately displays a complete table of all metadata fields with their current values, risk levels (high, medium, low), and whether they are personal identifiers or tracking fields. The Privacy Dashboard shows the total count of metadata fields, personal identifiers, custom fields, and tracking fields with a privacy score from 0-100.

Is EPUB validation performed before download?

Yes. The tool validates the EPUB structure including ZIP integrity, mimetype file, META-INF/container.xml, OPF package references, manifest entries, spine reading order, and XML syntax. The Processing Report displays the validation status, and the Verification Panel confirms 'Validation Passed: Yes' before download.

Can I use this tool on mobile devices?

Yes. The EPUB Metadata & Privacy Editor is fully responsive with a mobile-first design. The metadata inspector is collapsible, sanitization controls are touch-friendly, and the download button remains accessible from any position. All processing happens locally, so it works on tablets and phones with modern browser support.

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Reviewed by FreeDeskTools Editorial Team

EPUB Metadata & Privacy Editor has been reviewed for accuracy, usability, privacy, and browser-side performance. FreeDeskTools tools are designed to run locally whenever possible, helping users complete tasks quickly without unnecessary data collection.

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