uSignPDF

What is PDF Metadata?

Beyond the visible text and images, PDFs contain hidden dictionaries of data that describe the document's origins, author, and creation tools.

The Document Information Dictionary

Historically, PDF metadata is stored in a specific object called the Document Information Dictionary (or `/Info` dictionary). It contains key-value pairs such as:

  • /Title: The document's title (often defaults to the filename if not explicitly set).
  • /Author: The creator of the document (sometimes pulled from the OS user account).
  • /Creator: The application that originally created the document (e.g., Microsoft Word).
  • /Producer: The application that converted it to PDF (e.g., Acrobat Distiller, macOS Quartz).
  • /CreationDate & /ModDate: Timestamps using a specific PDF format (e.g., D:20240101120000Z).

XMP Metadata

Modern PDFs also use XMP (Extensible Metadata Platform), an XML-based metadata standard developed by Adobe. XMP data stream is embedded within the PDF and can contain much richer information.

Privacy Implications

When you share a PDF, you share its metadata. Use our Metadata Inspector tool to review what you are sending.