How to remove metadata from a PDF

Removing metadata from a PDF is done in PDF by Zaweba with Protect, then Remove hidden information. It lists what the PDF carries, with counts, so you can tick what to remove. If you want all of it gone in one go, Sanitise document does that. You can also edit single fields such as the author in Document properties. The app is free and works offline on Windows.

Metadata is information about the document rather than in it, and PDFs pick up a surprising amount of it on their way through different programs.

What metadata a PDF can carry

Document details hold the title, author, subject and keywords. XMP is a second, richer store of the same kind of thing, often written by the program that made the file, and it can include the software used and editing history. Beyond that, Remove hidden information also covers attached files, comments, form fields, invisible text, content off the page, bookmarks, scripts and actions, links, and earlier versions of the document saved inside the file.

Not all of that is metadata in the strict sense, but all of it can tell a reader more than you meant to.

Removing it step by step

Open the document and choose Protect, Remove hidden information. Look at the list and the counts. A file with nine comments and two attached files that you'd forgotten about is a useful thing to learn before sending it.

Tick the items you want removed. For a clean copy to send outside your organisation, document details, XMP, comments, attached files and earlier versions are the usual choices. Save as a new file.

If you'd rather not choose, Sanitise document removes everything on the list at once. That's the quickest route for a file going to the public.

Editing instead of removing

Sometimes you want to keep metadata but correct it, perhaps because the author field shows a previous employee or a template's name. Document properties (Ctrl+D) lets you edit the title, author, subject and keywords. File, Additional metadata (XMP) edits common fields, lists every property, and imports and exports .xmp files. File, Custom properties adds your own fields.

A sensible routine for a file you publish is to remove the clutter, then set a clear title and author yourself, so search engines and readers see what you intended.

Easy things to miss

Don't forget earlier versions. Ordinary saves in a PDF are incremental, which means an older state of the document can still be in the file. File, Earlier versions in PDF by Zaweba opens each incremental save in a tab of its own, which is a striking way to see the problem. Removing earlier versions, or using Save as, deals with it.

Removing metadata doesn't remove text on the page. If the content itself is sensitive, redact it first, then remove hidden information.

Doing a folder at once

Tools, Actions are saved lists of steps that can include removing hidden information and sanitising, and they run on files, a folder or the open document. There's a built-in action called Prepare for distribution for this kind of job. Everything runs on your own PC.