How to Split a PDF by Bookmark or Chapter — Auto TOC Detection

[AndrewYao93]

How to Split a PDF by Bookmark (Table of Contents)

When a PDF has real bookmarks — the structured tree Adobe Acrobat shows in its left panel — splitting at each bookmark is the fastest way to get one file per chapter, one file per invoice, or one file per exhibit. Y2Pal PDF Splitter auto-detects bookmarks and presents them as checkboxes.

Bookmark-Based vs Page-Range Splitting

Aspect	Bookmark mode	Page-range mode
Input required	Just click chapters	Type range numbers
Accuracy	Matches source structure	Depends on user typing
Works on scanned PDFs	Only if bookmarks exist	Always
Naming	Uses bookmark titles	Uses range (e.g. 1-5)

Bookmark mode is the right choice when the document already has structural TOC — textbooks, legal bundles with exhibit bookmarks, multi-invoice statements, etc.

Step-by-Step Guide

Step 1: Confirm the PDF Has Bookmarks

Open the source PDF in Adobe Reader, Preview, or Chrome's built-in viewer. Look for a sidebar labeled Bookmarks or a tree icon. If the sidebar is empty, there are no structural bookmarks — a visual TOC on a page does not count.

Step 2: Upload to Y2Pal

Visit y2pal.com/split-pdf and upload the PDF.

Step 3: Select Bookmark Mode

Y2Pal auto-detects bookmarks. If found, the "Split by bookmark" option is available with a tree view of detected entries and their page numbers.

Step 4: Choose Bookmark Depth

• Top-level only (default): each top-level bookmark becomes one file.
• Deeper levels (advanced): if the PDF has nested sub-chapters, choose how deep to split.

Step 5: Review Output Names

Each output file is named after its bookmark title. Review and edit names before confirming — bookmark titles sometimes contain characters that are illegal in file names.

Step 6: Split and Download

Click Split PDF. Output PDFs appear with their bookmark titles.

What Counts as a Bookmark?

Source	Has Structural Bookmarks?
Exported from InDesign/Word with TOC	Yes
Exported from LaTeX with hyperref	Yes
Scanned book, text-OCR only	No (add manually)
Bundled PDF with click-to-page nav	Yes
Printed visual TOC (text on page 3)	No

Adding Bookmarks to a PDF That Lacks Them

If your PDF has no bookmarks, add them first in a desktop editor:

1. Open in Adobe Acrobat Pro or a free alternative (PDFescape, Foxit).
2. Add one bookmark per chapter at the correct page.
3. Save and re-upload to Y2Pal.

Alternatively, use page-range mode with manually noted chapter start pages.

Tips

1. Clean up bookmark titles before splitting if they contain slashes or special characters — the tool sanitizes, but manual review avoids awkward file names.
2. For deeply nested bookmark trees, start with top-level only; nested splits can multiply files unexpectedly.
3. Bookmark mode is unavailable if no bookmarks are detected — use page-range mode as a fallback.

Requirements

• Source PDF with structural bookmarks.
• A browser that supports modern JavaScript (Chrome 90+, Firefox 88+).

Open Y2Pal PDF Splitter → | Back to README →