How to add bookmarks to a long PDF

Adding bookmarks to a long PDF takes a single keystroke in PDF by Zaweba. Go to the page you want, select the heading text if there is one, and press Ctrl+B; the bookmark is named after the selected text, or after the page label if nothing is selected. For a document that already has proper headings, you can make the bookmarks from those headings in the accessibility tools instead of one by one.

Bookmarks are the clickable outline that appears down the side of a PDF. In a manual, a thesis or a bundle of contracts they turn a hundred-page scroll into something you can jump round in a second, and readers notice when they're missing.

Planning the outline

Just the PDF and a sense of how it should be organised. It helps to know the main sections before you start, so the outline has a clear shape: chapters at the top level and sections inside them.

Adding and arranging bookmarks

Open the Bookmarks panel. Go to the first page you want to mark, select the heading text on the page and press Ctrl+B. Selecting the text first saves typing, because the bookmark takes its name from it.

Carry on through the document. If a name needs changing, select the bookmark and press F2 to rename it. Delete removes one you don't want.

Then shape the outline. Move up and move down change the order. Put under the one above makes a bookmark a child of the bookmark above it, which is how sections go inside chapters. Take out a level does the reverse. There's also a command to go to the page in view, handy when you have scrolled away and want the panel to catch up.

Each of these changes is one undoable step, so you can try an arrangement and undo it if it reads badly.

The quicker way for structured documents

If the document is tagged, or you are tagging it for accessibility anyway, bookmarks can be made from its headings. Tools > Accessibility can tag a document automatically, judging headings by their size, and once that's done the headings become a ready-made outline. Check it afterwards, since a big pull quote can be mistaken for a heading.

An outline readers can use

Keep names short. The panel is narrow, and "3.2 Installation" is easier to scan than a full sentence.

Don't go too deep. Two or three levels are plenty for most documents. A bookmark for every paragraph defeats the purpose.

Use style and colour sparingly. A bookmark's style and colour can be set, which is useful for picking out something like an appendix or a section that needs signing, but a rainbow outline is harder to read than a plain one.

Think about actions. A bookmark can do more than go to a page: it can open a web address, open a file or run a menu command. A bookmark called "Latest version online" that opens a web page is a neat touch for a document that gets updated.

Reading with bookmarks

When readers open the panel, they click an entry to go to its page, and the bookmark for the page in view is shown in bold, so they always know where they are. Expand all and collapse all help with a big outline.

Bookmarks also pair well with page labels. If the front matter is numbered i, ii, iii and the body starts at 1, bookmarks made without selected text take the label, so they match what the reader sees printed on the page.

Ten minutes spent bookmarking a long PDF in PDF by Zaweba saves every reader far more than that.