Hidden Metadata in Your PDF and How to Remove It

What is PDF metadata?

PDF metadata is descriptive information stored inside the file but not shown on any page: title, author, subject, keywords, the apps that made the file, and creation and modification dates. It is written automatically when a document is exported.

It lives in two places. The first is the document information dictionary, a short list of eight standard fields that has been part of PDF since the 1990s. The second is an XMP packet, a block of XML based on the Extensible Metadata Platform that Adobe introduced in 2001. XMP usually repeats the same values and can add more, such as document IDs and an editing history. The current PDF standard, ISO 32000-2, prefers XMP and deprecates most of the older dictionary, but nearly every app still writes both. A cleaner that clears only one leaves the other behind.

How can I see the metadata in a PDF?

Open the document properties in your PDF reader. Every desktop reader has them, usually under the File menu. Phones rarely show them, so use a browser tool there.

How do I remove metadata from a PDF?

Open the PDF in a metadata tool, choose to remove everything, and save a new copy. On this site the whole job runs in the browser, so a confidential document does not have to be uploaded to be cleaned.

• Open Remove PDF Metadata and choose the PDF. If it is password-protected, enter the password when asked.
• Review the list of fields found in the file.
• Choose Remove all to clear every entry and delete the XMP packets from the document and its pages. Or choose Edit fields to set a clean title and author and blank the rest.
• When editing, keep Remove XMP metadata ticked. XMP cannot be edited field by field, so leaving it in place can leave the old values behind.
• Download the new file. A before-and-after table shows the values read back from the saved file, so you can see what a reader will now show.

Fix it at the source too

Metadata keeps coming back if your apps keep adding it. In Word, Excel and PowerPoint on Windows, File > Info > Check for Issues > Inspect Document finds and removes author names, comments and revision data before export; Microsoft describes each category in Remove hidden data and personal information. In the Save As PDF dialog, Options has a Document properties checkbox you can untick.

The author name comes from File > Options > General > User name on Windows, and from the app's preferences or your user account on a Mac. Templates are the other common leak: a letterhead file created by someone who left years ago still stamps their name on every document made from it. Open the template, clear its properties once and save it.

Scanner apps and phone scanning features are usually more modest. They tend to record the app name and the time, not a person's name. It is still worth a look, because some office scanners write the device's network name or the signed-in user into the Author field.

What does metadata removal not remove?

It does not touch anything that is part of the pages. Clearing the properties is not the same as sanitising a document, and several other places can hold personal information.

Think of metadata as the label on a folder. Removing the label tells a reader nothing about who filed it, but everything inside the folder is still there. Go through this list for any document where your identity or a client's identity matters.

• Visible text, headers and footers, including names in signature blocks.
• Comments and annotations: each stores the reviewer's name and a timestamp. Delete them, or merge them into the page with Flatten PDF if the names are not sensitive.
• Text under black boxes: a drawn rectangle hides nothing. Use Redact PDF for content that must be gone.
• Content outside a cropped area: cropping changes the visible box and the rest of the page stays in the file.
• Embedded photos: images placed in a document can carry their own Exif camera data, sometimes including location.
• Form field values and attached files.
• The file name: “Jane_Doe_resignation_draft.pdf” reveals more than any metadata field.

A five-step check before a document leaves your hands

For anonymous submissions and anything sent outside your organisation, this routine takes about a minute.

• Look at the document properties in your reader or in Remove PDF Metadata.
• Remove all metadata, or replace author, title and keywords with neutral values.
• Look for comments, form data and hidden content; flatten or redact where needed.
• Rename the file to something neutral and descriptive.
• Open the final file once more and check the properties again.

When is metadata worth keeping?

Keep it when the document is public, archived or might become evidence. A good title helps search engines and screen readers describe a file, and browsers show the title in the tab instead of a file name.

For published reports, replace personal fields with useful ones rather than leaving everything blank: a descriptive title, the organisation as author, a few keywords. Accessibility standards such as PDF/UA expect a title to be set. Scanned documents often record the scanner model and the scan date, which can matter in a dispute about when a document existed, so keep an untouched original before cleaning anything that may be needed later. Strip metadata completely for anonymous submissions, peer review, whistleblowing, legal disclosures, and anything sent to another organisation from an internal template.