Reads Raw Outline Metadata
Splits using the actual PDF data structure, not visual text parsing.
Split PDF Using the PDF Outline
The PDF outline is your document's structural blueprint - iMZi PDF uses it to split with complete precision.
What Is the PDF Outline?
The PDF outline - sometimes called the document outline or navigation tree - is the formal data structure stored in every bookmarked PDF.
Unlike the visual table of contents (a formatted text page), the PDF outline is machine-readable metadata embedded in the file itself. It stores every section's title, its nesting level, and the exact page destination it points to.
When iMZi PDF splits using the PDF outline, it is reading this precise metadata - not attempting to parse visual text - which guarantees accurate split points regardless of how the document is formatted.
How to Split a PDF Using Its Outline Structure
The PDF outline provides unambiguous split coordinates - iMZi uses them directly.
1. Upload the Outlined PDF
Upload a PDF that includes an outline (visible in the bookmarks panel of any PDF reader).
2. Inspect the Outline Tree
iMZi displays the detected outline entries, showing title and level for each node.
3. Split and Export
Set the desired outline depth and click Split PDF. Each outline entry produces one export file.
Why Outline-Based Splitting Is the Most Precise Method
The outline is the authoritative source of document structure - nothing is more accurate.
Multi-Level Outline Support
Handle flat outlines or deeply nested hierarchies with equal accuracy.
Depth Control
Choose to split at outline level 1, 2, 3, or any combination.
Exact Page Targeting
Each outline entry's stored page destination is used as the split coordinate.
Reliable for Complex Documents
Works correctly even on PDFs with hundreds of nested outline entries.
No Cost
Outline-based splitting is completely free on iMZi PDF.
Outline vs. Bookmark vs. TOC - What's the Difference?
In PDF terminology, the outline and bookmarks refer to the same underlying data structure. The "table of contents" usually refers to the visual TOC page, while the PDF outline is the embedded, machine-readable version. iMZi PDF uses the embedded outline for splitting - which is faster and more reliable than trying to parse the visual page.
PDF Types That Benefit from Outline-Based Splitting
Structured, formally produced PDFs almost always include a proper outline.
InDesign-exported publication PDFs
Word documents converted to PDF with styles
LaTeX-compiled academic papers
FrameMaker technical documentation
Government-issued formal reports
EPUB-to-PDF converted e-books
Frequently Asked Questions
Find answers to common questions about this tool.
Split Your PDF Using Its Built-In Outline Structure
Outline metadata provides the most precise split coordinates available in any PDF.