A well-made PDF already contains the cut list: its bookmarks. Splitting by bookmarks follows that structure, so chapters become files with the right names instead of page ranges you have to type and check.
Step by step
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1
Upload your PDF
Drag your PDF onto the box or click Choose file. It is sent over an encrypted connection and only used for this task.
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2
Set the options
Adjust bookmark level, contains text (optional), include extra page at the end and file name pattern. Every field has a sensible default, so you can usually run the tool straight away.
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3
Uses the existing bookmarks
A bookmark marks where its section begins, and the section runs to the page before the next one. Bookmark level picks which depth splits: 1 for the chapters themselves, 2 to cut inside them. If the document has no bookmarks this tool cannot guess the chapters — use Split by text instead.
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Run it and download
Press Split by bookmarks and the page shows progress while it works. When it finishes you get a download link — nothing is emailed and nothing is stored longer than it needs to be.
How a bookmark defines a section
A bookmark marks where its section begins; the section runs to the page before the next bookmark at the same level. Level 1 usually means the main chapters, level 2 cuts inside them, and so on. Choose the shallowest level that matches the parts you actually want.
Levels, filters and the extra page
“Contains text” filters bookmarks by title, useful when the outline mixes appendices or index entries. “Include extra page at the end” keeps a divider or blank page that follows a section. Preview the resulting list before exporting; a wrong level can create dozens of tiny files.
Names and the final check
The default name pattern uses the bookmark title and part number. Open the first and last part and confirm the chapter boundaries and page counts. If the PDF has no bookmarks, there is nothing to follow — create them with Create Bookmarks or use Split by text.
Good habits for Split by bookmarks
- Page thumbnails are tap-friendly, so you can reorder and delete on a phone.
- Every tool works on a copy — your original file is never modified.
- Use Split by text when a document has no bookmarks to split on.
Common questions
Is this tool free?
Yes. Every tool on this site is free to use, with no sign-up, no watermark and no daily task limit.
Do I need to install anything?
No. The tools run in your browser and are processed by this server.
What happens to my files?
They are stored under an unguessable id and swept automatically after a couple of hours. Nothing is shared or indexed.
Does it work on a phone?
Yes. The page pickers and editors are built for touch, so dragging, rotating and selecting pages all work without a mouse.
What does Split by bookmarks do exactly?
Uses the document's bookmarks: each chapter becomes a separate file.
What if my PDF has no bookmarks?
Split by bookmarks cannot infer chapters. Use Split by text or add bookmarks first with Create Bookmarks.
What does bookmark level 2 do?
It cuts at the second level of the outline, which can be useful for subsections but usually produces more, smaller files.
Are bookmarks kept in each part?
Bookmarks inside each part are carried where possible. Check one part’s contents panel after the split.