What can a PDF reveal?
A PDF is more than the pages you see. Alongside the text and images, the file can carry information about itself: who made it, with what software, and when. Most of it is added automatically, which is why it's easy to share without noticing. Checking a PDF before it leaves your hands takes a few seconds.
PDF metadata
Every PDF can store a small set of document properties, usually visible in a viewer's “Document properties” panel:
- Author
- Often copied from the computer account or app profile that created the file, so it can contain your name, a colleague's, or the name of whoever made the original template.
- Creator
- The application the document was first made in, such as a word processor or design tool.
- Producer
- The software that generated the PDF itself, frequently with a version number.
- Title and Subject
- Free text that can differ from the file name and sometimes keeps an internal or earlier name for the document.
- Keywords
- Search terms or tags, occasionally left over from a template.
- Dates
- When the file was created and last modified, usually with a time zone.
None of these fields is a problem in itself. They're worth reviewing when a document is going to a client, an employer, a publisher or the public. If you'd rather not share them, the PDF Metadata Remover can remove them and create a cleaned copy in your browser. To see every stored value, use the PDF Metadata Viewer; to change values instead, use the PDF Metadata Editor.
XMP metadata
Many PDFs keep a second metadata record in a format called XMP, written as XML inside the file. It often repeats the author, title and dates, and it can add unique document IDs and details about the software used. Removing only the standard fields can leave this copy behind, which is why the checker reports it separately.
Comments
Review comments are stored as annotations attached to a page. Sticky notes can show only as a small icon, and many viewers hide comments unless a comments panel is open, so they're easy to send without noticing. The checker counts supported comments (sticky notes and text-box comments, including replies), shows which pages they're on, and lets you view each comment's author and text. If you'd rather not share them, the Remove Comments From PDF tool removes them and re-checks the copy. Other annotations are counted by group: highlights and text markup, drawings and shapes, stamps, links and form controls. When review markup is found, the Remove Annotations From PDF tool can remove it while keeping links and form fields.
Form fields
Fillable PDFs keep the values typed or selected in each form field, and fields can also store a default value. The checker lists the supported form fields and says which ones hold a stored value, without showing the values themselves. When values are found, the Clear PDF Form Fields tool can clear them while keeping the form. To keep the answers visible but stop them being edited, Flatten PDF turns them into page content (flattened values are still readable in the file).
Embedded attachments
A PDF can carry complete files inside it, such as spreadsheets, images or other documents. The checker lists each embedded file's name, type, size and where it's referenced, without opening or extracting it. The Remove PDF Attachments tool can remove the ones you choose.
JavaScript & actions
PDFs can carry actions that run when the file or a page opens, when a form is used or when a link is clicked, including JavaScript. The checker reports scripts and other executable actions separately from ordinary web links and internal navigation, without running anything. The Remove JavaScript From PDF tool can remove them.
Digital signatures
Some PDFs contain a digital signature. The checker tells you when it finds a signature structure, because changing or rebuilding a signed PDF, including cleaning its metadata, can invalidate the existing signature. It doesn't check whether a signature is valid or who signed it.
PDF/A identification
PDF/A is a version of PDF intended for long-term archiving, and a PDF/A file declares this in its XMP metadata. The checker reports that declaration so you know that removing metadata may affect how the file identifies itself. It reads the identification only; it doesn't validate whether the file actually meets the PDF/A standard.
How to check a PDF before sharing it
- Drop the PDF into the checker above. It's read in your browser and never uploaded.
- Look at the highlighted items, especially the author, title and any custom properties.
- If there's something you don't want to share, use the PDF Metadata Remover to create a cleaned copy.
- Read through the pages themselves: names and notes can also appear in the visible content.
What the checker does not inspect yet
This version focuses on document metadata, supported comments and annotations, supported form fields, embedded attachments, JavaScript and document actions, and a few document characteristics. A PDF can contain other things that aren't checked yet, including:
- note text attached to highlights, stamps and drawings (these annotations are counted, not read),
- hidden or covered page content, including text under a black box that was never truly redacted.
Redaction safety isn't automatically determined for existing third-party PDFs. To redact content yourself, use Redact PDF, which verifies its own output.
So a report with nothing to review is useful, but it isn't a guarantee. Read through the document itself before sharing anything sensitive.