Metadata is information about the PDF
A PDF contains the content you can see—text, images, graphics and form controls—but it can also contain information that describes the document itself. That descriptive information is metadata. Common examples include a document title, author name, keywords, the software used during creation, and creation or modification dates.
Metadata is useful for cataloguing, searching, document management and workflow automation. It can also reveal details that a person did not intend to share, which is why inspecting metadata can be useful before publishing or sending a document outside an organization.
Where PDF metadata is stored
Document Information dictionary
The traditional PDF Info dictionary can hold standard fields such as Title, Author, Subject, Keywords, Creator, Producer, CreationDate and ModDate. PDF also allows custom string-valued Info entries.
XMP metadata
XMP is an extensible metadata model commonly serialized as XML. In PDFs it can carry overlapping descriptive fields plus document and instance identifiers, language information, metadata timestamps, PDF/A declarations, and application-specific properties.
Because XMP is extensible, software can define additional namespaces beyond the common properties a general-purpose viewer recognizes.
Common PDF metadata fields
Can PDF metadata be trusted?
Metadata can be useful evidence about a workflow, but ordinary metadata fields are editable. A file may have been converted, rewritten, cleaned, or processed by software that changed the values. For that reason, an Author name or timestamp should not be treated as cryptographic proof of authorship or chronology.
The most useful approach is to consider multiple signals together: Author, Creator, Producer, timestamps, document IDs, the visible content, digital-signature status, and the context in which the file was obtained.
How Lyonite inspects PDF metadata
Lyonite's PDF Metadata Viewer reads the PDF locally in your browser. It inspects standard Document Information fields and, when present and decodable, the active document-level XMP stream. It also reports useful structural context such as PDF version, page count, encryption status, signature-related structures, forms, font embedding and image objects.
The viewer intentionally distinguishes practical inspection from forensic validation. For example, a PDF/A declaration in XMP is reported as a declaration rather than a guarantee that the entire document conforms to the PDF/A standard.
Inspect PDF metadata in your browser →