Split a PDF into One File per Bookmark
Break a PDF into one file per top-level bookmarked section.
Select a PDF
Click to choose, or drop a file here
You can also paste (Ctrl+V / Cmd+V)
Most tools run entirely on your device
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About splitting a PDF by bookmark
A long PDF with a proper bookmark outline — a report with chapters, a manual with sections — already has natural break points built in. This tool uses that existing outline to split the document automatically: one output file per top-level bookmarked section, instead of you having to work out and type the page ranges yourself.
It reads the PDF's bookmark (outline) structure to find where each top-level entry starts, then builds a separate PDF for each section using pdf-lib, entirely in your browser. If the document has no bookmarks, there's nothing for this tool to split on — use Split PDF's manual page-range mode instead, or add an outline first with Add PDF Bookmarks.
Supported files
Accepts a PDF with a bookmark outline. Produces one PDF per top-level bookmarked section, zipped together.
Is my file uploaded?
No. Splitting runs entirely in your browser with pdf-lib — nothing is uploaded.
Common problems
- "No bookmarks found"
- The PDF doesn't have an outline/bookmark structure — not every PDF does. Use Split PDF's page-range mode instead, or build an outline first with Add PDF Bookmarks.
How to Split PDF by Bookmark
- 1
Add your PDF
It must have bookmarks.
- 2
Split
One file is created per top-level bookmarked section.
- 3
Download the zip
Every section, named after its bookmark.
Split PDF by Bookmark — frequently asked questions
My PDF has no bookmarks — what happens?+
The tool tells you and you should use Split PDF with page ranges instead.
What about nested bookmarks?+
Only the top-level bookmarks are used as split points.
Is there a free way to split a PDF into one file per bookmark?+
Yes — this tool splits by bookmark entirely in your browser, free and with nothing uploaded.
Does it work on a PDF with only one bookmark?+
Yes, though the result is effectively unchanged — bookmark splitting only matters once there are at least two top-level entries.
Do you upload my files to a server?+
No — every tool here processes your files entirely on your device, and nothing is uploaded to a server. The only exception is the AI tools, which send the extracted text (not the file) to Claude to do their work.
Is there a file size limit?+
There's no artificial limit we impose, but since processing happens in your browser, very large files (500+ MB or 1,000+ pages) are limited by your device's memory rather than by us.
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