What your PDF reveals: metadata, privacy and how to clean it
PDFs hide the author's name, the software used and the dates. See what yours says, edit it, remove it, and flatten filled forms before you send the file.
When you send a PDF, you are sending more than the pages you can see. Hidden inside the file is information about it: a title, an author’s name, the program that made it, when it was created and last changed. Usually this is harmless. Sometimes it gives away what you meant to keep to yourself. Here is what PDFs carry and how to check and clean yours.
What is metadata?
Metadata is data about the document rather than part of its content. A PDF commonly stores:
- Title, which many programs fill in from the first heading or the file name.
- Author, often copied from the name registered in Word or the computer’s user account. This is the one that most often reveals a real name.
- Subject and keywords, if anyone entered them.
- Created with and PDF producer, the programs involved, sometimes with version numbers.
- Creation and modification dates and times.
- A second copy of much of this in a hidden XML block, called XMP metadata.
It does not show up when you read the document, but it appears in the file’s properties in any PDF viewer, and in search engines that index PDFs.
Why it matters
- A document you publish anonymously may still carry your name as the author.
- A “final” file can show it was created weeks before, or edited yesterday, which may not be what you want a client or counterparty to know.
- An old title, left over from a previous draft or another client’s document reused as a template, can be embarrassing or even confidential.
Look inside your PDF
- Open PDF Properties & Metadata and add the file.
- The details panel shows the page count, the page sizes (named, for example A4 or Letter), the PDF version, the creation and modification dates, and whether the file has fillable form fields.
- The form on the left shows the title, author, subject, keywords, “created with” and producer for you to read.
Edit it or remove it
To correct the details, change the fields and click Save with these details. A tidy title and a company name in place of a personal name look more professional, and a proper title shows in the browser tab when someone opens your PDF.
To clean the file before sharing, click Remove all metadata & download. It clears the title, author, subject, keywords, creator and producer, removes the dates, and deletes the hidden XML copy.
What this does not remove. Metadata removal does not touch the pages. Names, comments or tracked changes that are visible in the text, images with their own details, or hidden layers still remain. If something sensitive appears in the document itself, you need to redact it as well. See how to hide details in pictures and why cropping is not redaction.
Flatten a filled form
A fillable PDF form keeps its answers in fields that can be edited by whoever opens the file. If you have filled in a form and want the answers fixed, so they cannot be changed and appear the same in every viewer, tick Flatten form fields before saving. The answers become part of the page, and the editable fields are gone. Keep an unflattened copy if you may need to change something later. After flattening you can add a signature with Sign PDF.
A quick checklist before you send a PDF
- Check the title and author in the properties.
- Remove the metadata if you want to stay anonymous or tidy.
- Flatten forms you have completed.
- Compress it if it is large, using Compress PDF, and number the pages if it is long.
The file is read and rewritten in your browser, so the document never reaches a server. See Are online file converters safe?.