Split a PDF into Chapters Using Its Bookmarks
or drop files here
If your PDF has a clickable outline in the sidebar, it already knows where every chapter begins. This tool uses those bookmarks to cut the file into named parts, lists each part with its page range before writing anything, and never sends the document anywhere.
The outline is already the plan.
Add a bookmarked PDF
Exported manuals, e-textbooks, theses and board packs usually carry an outline. Files locked with an opening password ask for it once.
Pick chapters or sections
Each bookmark is matched to the page it opens. Keep the top level for chapters, or go a level deeper for sections, and read the file list before you commit.
Save the ZIP
Every part becomes its own PDF, named after its bookmark and numbered in book order, all packed into a single ZIP.
When a long PDF should arrive one chapter at a time.
Big documents are written as a whole but read in pieces. When the author added bookmarks, those pieces are already marked out for you.
Textbooks and technical manuals
A 700-page service manual is awkward on a phone or a workshop tablet. Split it into chapters and open only the procedure you need, with the file name telling you what is inside.
One section of a contract or report
Send a supplier only the schedule that concerns them, or a client only the findings chapter, without forwarding the rest of the document along with it.
Course readers
A compiled reader normally has a bookmark per article or per week. Splitting it lets you post each reading on the course page as its own file, so nobody scrolls through 400 pages to find this week's text.
Reading on e-readers
E-ink readers and older tablets can be slow to open and page through very large PDFs. Smaller files, one per chapter, are lighter to load and easier to find in a library.
Board and committee packs
Packs compiled with a bookmark for each agenda item can be split so every paper goes to the person presenting it, or is filed next to the minutes for that item.
Hearing and data room bundles
Bundles prepared for a hearing or a due diligence review are typically bookmarked by tab or exhibit. Split them to cite, replace or share one exhibit without handling the whole bundle.
From bookmark tree to finished files.
Take a 96-page field service manual with two levels of bookmarks. The same file gives a different set of parts depending on the level you split at, and two details are worth checking in the preview list before you save.
The bookmarks in the sidebar
- Safetyp. 7
- Lockout procedurep. 7
- Protective equipmentp. 12
- Installationp. 19
- Site preparationp. 20
- Wiringp. 31
- Maintenancep. 48
- Daily checksp. 48
- Replacing filtersp. 61
- Indexp. 90
Pages 1 to 6 (cover, copyright and contents) have no bookmark.
Split at Top level
5 files, one per chapter
- 01 Front matterpages 1 to 6
- 02 Safetypages 7 to 18
- 03 Installationpages 19 to 47
- 04 Maintenancepages 48 to 89
- 05 Indexpages 90 to 96
Split at Level 2
7 files, one per section
- 01 Front matterpages 1 to 6
- 02 Lockout procedurepages 7 to 11
- 03 Protective equipment (see note)pages 12 to 19
- 04 Site preparationpages 20 to 30
- 05 Wiringpages 31 to 47
- 06 Daily checkspages 48 to 60
- 07 Replacing filters (see note)pages 61 to 96
* Also holds a page that belongs to the next chapter. See the notes below.
What to notice in the Level 2 result
File 03 ends on page 19, which is the title page of Installation. A deeper split only looks at bookmarks on that level, and no section bookmark starts on page 19, so the page stays with the section before it.
File 07 runs to page 96, because Index is a top-level bookmark with no sections under it. With nothing on level 2 to start a new file, its seven pages are attached to Replacing filters.
Neither of these is a fault in the manual. If you want chapters, the top level is the clean choice. If you need sections and the stray pages matter, move them first with Organize PDF, or take the affected file afterwards and trim it by page range with Split PDF.
Rules the splitter always follows
- Pages before the first bookmark on the chosen level become a file called Front matter.
- Same-level bookmarks that open one page are merged, and the first title in the outline names the file.
- Bookmarks that open a web address, or whose target page cannot be found, are ignored.
- Files follow page order, even when the outline lists its bookmarks in a different order.
- Each page is copied by pdf-lib as it stands, so text and images come out exactly as they went in.
Questions answered.
What if my PDF has no bookmarks?
Is a bookmark the same as the contents page?
Why is the split button greyed out?
Can I split at sections instead of whole chapters?
What happens to the cover and contents pages?
What if two bookmarks open the same page?
How are the files named?
Do the new files lose quality or keep the bookmarks?
Is anything sent to a server while I split?
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