When you receive a highly sensitive PDF document (such as a legal contract or an anonymous manuscript), you should never assume the document is completely clean. PDF files contain deeply embedded layers of invisible metadata that can reveal the exact software used to create the document, the date it was authored, and even the full name of the original author. You can easily expose and inspect all of this hidden data without any professional software by using the built-in macOS Preview application.
How to Open the Document Inspector
The metadata reader is completely hidden from the standard reading interface to keep the application looking clean.
- Double-click your PDF document to open it in Preview.
- Look at the main menu bar at the absolute top of your Mac screen.
- Click the Tools menu.
- Select Show Inspector from the drop-down menu (or simply press Command + I on your keyboard).
A small, floating window will instantly appear on your screen, containing multiple tabs filled with technical information.
How to Read the General Information Tab
Ensure that the first tab, the General Info tab (represented by an icon of a magnifying glass over a piece of paper), is actively selected.
This panel reveals the most critical embedded metadata, pulling data directly from the PDF file’s internal dictionary:
- Author: This field often automatically populates with the registered name of the computer that originally generated the PDF. If someone tried to send an anonymous document but left their name in the Author field, you will see it here instantly.
- Title & Subject: These fields are often populated automatically by Microsoft Word or Apple Pages when the document is exported.
- Creator / Encoding Software: This tells you exactly what engine built the file (e.g., “Microsoft Word for Mac” or “Adobe InDesign”).
- Creation Date: This reveals the exact second the file was originally authored, completely ignoring when the file was downloaded or emailed to you.
Checking Encryption and Security
If you click the third tab in the Inspector window, the Encryption tab (represented by a padlock icon), you can inspect the document’s security restrictions.
This panel explicitly lists whether the document has been cryptographically locked. It will tell you if the author has legally restricted your ability to print the document, copy text to your clipboard, or extract images. If you are struggling to edit a document, this metadata panel will instantly tell you if the file is protected by a master password.