Auto Generate Bookmarks
Find the headings of a PDF by the size of their type and their numbering, look through the list, and add nested bookmarks. Free, in your browser.
About This Tool
Auto Generate Bookmarks finds the headings of a PDF and gives it a bookmark for each, so that the document has a clickable outline in the bookmarks panel of a PDF reader.
Headings are found in two ways, together or one at a time. The first is the size of the type: a line set clearly larger than the body of the document is a heading, and you can name the smallest size that counts instead of leaving it to the document. The second is numbering: lines that begin the way headings are numbered, such as "2.3 Method", "Chapter 4", "Appendix B", "الفصل الثاني" or "第三章". A line that begins with a single number, as the items of a numbered list do, counts only when it is also set larger than the text. The text is read a line at a time and in reading order, so Arabic headings and headings set in more than one typeface are found whole. Bold type alone does not make a line a heading.
What was found is listed before anything is written, each heading with its page, and you untick whatever is not one. The bookmarks are nested by level: a section such as 2.1 goes under its chapter. Each bookmark opens the top of the page its heading is on. If the PDF already has bookmarks, the new ones replace them, and the page says so first. The pages themselves are not changed, and everything happens in your browser.
How to Use
Upload your PDF
Drag one PDF onto the box, or click it to choose a file. The PDF must contain real text: put a scan through OCR PDF first.
Choose how headings are found
Under "Look for", choose larger type and numbered headings together, or one of the two. If the headings are not much larger than the text, type the smallest heading size, in points.
Find and look through
Click "Find headings". The list shows each heading with its page, set in by its level. Untick the lines that are not headings.
Add and download
Click the button that adds the bookmarks, then "Download". To look another way, change the setting and click "Find headings" again.
Use Cases
Manuals with numbered sections
Get a bookmark for every numbered heading, the sections under their chapters, so that readers can jump straight to 4.3.
A first outline for a thesis
Let the tool pick out chapter titles by their larger type, drop the lines that are not headings, and arrange the result further in Edit Bookmarks.
Long reports and e-books
Add an outline to a text PDF that has none, so that it is easier to move around in on a tablet or phone.
Frequently Asked Questions
Can I add my own heading patterns?
No. The numbering the tool knows is built in: section numbers such as 2 or 2.3.1; the words Chapter, Part, Book, Unit, Section and Appendix followed by a number; their usual Arabic counterparts, such as الباب, الفصل, القسم, المبحث and الملحق; and Chinese chapter marks. Headings written any other way are found by the size of their type.
Are the bookmarks arranged in levels, such as chapters and sections?
Yes, in up to three. By numbering, 2 is a chapter, 2.1 a section under it, and 2.1.3 one level lower; by size, the largest headings are the first level. You can rearrange the result in the Edit Bookmarks tool.
Does it change my pages or the bookmarks I already have?
The pages are not changed. The bookmarks the PDF already has are replaced by the new ones, and the page tells you how many there are before you add anything. If no heading is found, the tool says so and makes no file.
Why is a line listed that is not a heading?
A line in large type, such as the title on a cover or a quotation set large, or a line that begins like a numbered heading, can be taken for one. That is why the list is shown first: untick such lines before you add the bookmarks.
Where does a bookmark take the reader?
To the top of the page its heading is on.