Each item stores a title, a place to go and, optionally, children that give the tree its levels. The standard defines the title as “The text that shall be displayed on the screen for this item.” The place to go is “The destination that shall be displayed when this item is activated”, or an action instead. Most files get their outline when they are made. Adobe notes that “Bookmarks are generated automatically during PDF creation from the table-of-contents entries of documents created by most desktop publishing programs.”

Are Preview’s bookmarks the same thing?

No. Preview shows a file’s outline from its View menu: “Show a document’s table of contents (if it has one): Choose View > Table of Contents.” Its Bookmarks sidebar is a separate feature, for pages you want to return to: “Add a bookmark: Choose Tools > Add Bookmark.” Apple’s guide describes viewing the outline, not editing it.

How do you rename a PDF bookmark on a Mac?

  • In Acrobat, select the bookmark in the Bookmarks side panel and choose Rename Bookmark from the panel’s Options menu.
  • In Preview, the guide documents adding and deleting Preview’s own bookmarks, not renaming the file’s outline: “Choose View > Bookmarks, Control-click the bookmark in the sidebar, then click Delete.”
  • With qpdf, the developer route: write the file as JSON, change the item’s /Title string in the JSON, and read it back.
$ qpdf --json-output "Report.pdf" report.json
$ qpdf "Report.pdf" --update-from-json=report.json "Report fixed.pdf"

qpdf’s help describes the second step as “Update a PDF file from a JSON file.” We ran the round trip on PDF Textfix’s demo contract with qpdf 12.4.2. Then open the result and check each bookmark against its page.

Why does a bookmark keep its old title after you edit the page?

Because the title is a string of its own, apart from the page. Change a heading on page 4, and the bookmark pointing there still reads as before. PDF Textfix copies the outline as it was: Help > Saving and Privacy names bookmarks among the things the saved file keeps and says it “can hold the same words”. So rename the bookmark too, and read the outline before you share the file.

What saving does to your PDF lists the other copies of text a page edit leaves alone; PDF Textfix and Apple Preview compares the two apps.

How do you list a PDF’s bookmarks?

In a viewer’s sidebar, or with qpdf, which prints them as JSON. None of the six demo documents has an outline; the demo contract, for example:

$ qpdf --json --json-key=outlines "Demo Contract.pdf"
  "outlines": []

pdfinfo’s -dests option lists the named destinations items may point to.

Questions about PDF bookmarks

Why are my PDF bookmarks not working?

A bookmark works only while its target exists. An item points to a page and a position, or to a named destination the file defines; when that page or name is gone, the click goes nowhere. pdfinfo -dests lists the names a file still defines.

How do I make a PDF open with the bookmarks panel?

Set the file’s page mode: the catalog’s PageMode value UseOutlines means “Document outline visible”. In Acrobat, it is part of Document Properties, whose Initial View tab “Controls how the document appears when opened”.

Why does my PDF have no bookmarks?

The app that made it wrote no outline. An outline is optional; apps that make one usually build it from the document’s table of contents.