PDF Metadata Editor

PDF files store metadata in two distinct locations within the file structure, and understanding both is essential for thorough metadata management. The first location is the Info Dictionary, a standard PDF object (defined in ISO 32000-2:2020, Section 14.3.3) that contains key-value pairs for Title, Author, Subject, Keywords, Creator, Producer, CreationDate, and ModDate. Every PDF reader and editor recognizes these fields. When you open a PDF's "Properties" or "Document Info" dialog in Adobe Acrobat, Preview, or any other viewer, the values displayed come from this dictionary.

The second location is the XMP Metadata Stream (Extensible Metadata Platform, ISO 16684-1), an XML-based metadata container embedded as a stream object in the document catalog. XMP metadata can store everything the Info Dictionary holds plus arbitrary additional properties: Dublin Core elements (dc:creator, dc:description), PDF/A conformance markers, rights management data, and custom application-specific fields. XMP metadata is extensible by design — any application can write its own namespace into the stream. Adobe Creative Suite, for example, writes detailed xmp:CreatorTool, xmpMM:DocumentID, and xmpMM:InstanceID fields that track document history across applications.

The privacy implications of PDF metadata are significant. The Creator field typically records the application name and version (e.g., "Microsoft Word 2021" or "LaTeX with hyperref v7.00e"), revealing the software environment. The Producer field identifies the PDF rendering library (e.g., "macOS Quartz PDFContext" or "Apache FOP 2.8"), which can fingerprint the operating system. Author fields may contain a person's full name pulled from OS user profiles without explicit consent. Creation and modification dates establish a documentary timeline that may be sensitive in legal or journalistic contexts. Keywords and subject lines can leak internal classification terms.

This tool uses pdf-lib, a JavaScript library that manipulates PDF structures at the object level. When editing metadata, pdf-lib modifies the Info Dictionary entries in place using its typed API: pdfDoc.setTitle(), pdfDoc.setAuthor(), and equivalent methods for each field. For sanitization, the tool additionally accesses the document catalog via pdf-lib's low-level API and deletes the Metadata entry, which removes the entire XMP stream. This dual-level approach ensures both the legacy Info Dictionary and the modern XMP stream are cleared.

Editing metadata is a non-destructive operation with respect to page content. The Info Dictionary and XMP stream are structurally independent from content streams, font programs, image XObjects, and annotations. Changing a metadata value modifies only the bytes of the relevant dictionary entry or stream object — no page content is decompressed, re-rendered, or re-encoded. The cross-reference table is rebuilt during serialization to reflect the updated object positions, but this is a standard part of any PDF save operation and does not affect content integrity.

Controlling PDF metadata addresses concrete needs across legal, corporate, and personal workflows:

• Public document distribution — Before publishing PDFs on a website or sharing them externally, organizations strip metadata to prevent leaking internal software versions, employee names, or draft timestamps. A contract exported from "John Smith's MacBook — Word 2021" reveals information that should not accompany a finalized public document.
• GDPR and data protection compliance — Under GDPR Article 5 (data minimization), personal data should not be included in documents beyond what is necessary. Author names and user account identifiers embedded automatically by PDF generators qualify as personal data. Sanitizing metadata before archival or transfer satisfies this requirement.
• Legal document preparation — Court filings, patent applications, and regulatory submissions often require specific metadata formatting. Title and subject fields must match case identifiers, and extraneous metadata from document assembly workflows must be removed to avoid confusion or inadvertent disclosure during discovery.
• Whistleblower and journalist protection — Leaked documents may contain metadata that identifies the creator's workstation, software license, or timezone. Sanitizing metadata before publication removes these forensic traces, protecting source anonymity.
• Document cataloging and search — Setting accurate Title, Author, and Keywords metadata improves document discoverability in digital asset management systems, SharePoint libraries, and desktop search indexes. Well-tagged PDFs surface in search results based on metadata before full-text indexing runs.
• PDF/A archival compliance — Long-term archival standards (PDF/A-1, PDF/A-2, PDF/A-3) require specific metadata fields to be present and correctly formatted. Editing metadata ensures the Title, Creator, and conformance-level fields meet validation requirements before submission to archival systems.

Cloud-based PDF metadata tools require uploading your documents to remote servers, which is unacceptable for confidential materials. This tool processes everything in your browser — the PDF never leaves your device, making it safe for classified documents, medical records, financial reports, and any file subject to privacy regulations.