Add Bookmarks to a PDF and Build the Outline
A 90-page PDF without an outline is a scroll bar. Bookmarks give it a table of contents in the viewer's sidebar.
What this tool does
Builds the navigation outline: one bookmark title per line, each pointing at a page, with an optional pattern that detects headings and creates the tree for you.
How it works
Type the titles in page order, or let the auto-detect pattern match headings such as “Chapter 3”, then choose whether to replace the existing outline or append to it. Bookmarks are what Split by bookmarks reads later, so a clean outline pays for itself.
- Choose the PDF, or drag it onto the page.
- Set bookmark titles (one per line) and existing bookmarks — the settings below explain what each one changes.
- Run the tool and download the result.
Settings that decide the result
- Existing bookmarks — Applies when the titles box is used. The bookmark editor always replaces the outline.
- Bookmark titles (one per line) — Add "@ 7" to send an entry to a page, and indent a line to nest it under the one above. Left blank, headings are detected automatically.
- Auto-detect pattern
The remaining 1 controls stay on the tool page, where each one sits next to the live preview.
When to reach for it
- A long document has no sidebar outline. One title per line is enough to build it.
- Headings repeat in a fixed pattern. Auto-detect finds them and creates the tree.
Questions we get
Why add bookmarks to a PDF?
They give the reader a table of contents — click straight to a chapter in any viewer. Existing outlines can be renamed, renumbered or extended too.
Can I nest a bookmark under another one?
Yes, three ways: press + on the row it should sit under, drag one row onto another, or pick a parent in the Add dialog's Parent bookmark box.
Where it fits
The tools people usually open next to Create Bookmarks:
- Page Numbers — Apply page numbering to PDF files.
- Extract Images — Save each image from the PDF as a separate file
- Grayscale — Make a PDF text and images grayscale
Every tool works on a copy, so the original file is never modified. Uploads are stored under an unguessable id and deleted automatically two hours after you last open them; nothing is listed, shared or indexed. More on the security page.