What are PDF bookmarks and how does the split tool use them?

PDF bookmarks (also called the document outline) are navigation anchors embedded in the file that correspond to chapters, sections, or topics. The Split by Bookmarks tool reads these anchors and splits the document at each one, producing a separate PDF per section.

What if my PDF has no bookmarks?

The tool requires a PDF with an existing bookmark structure. If your document has no bookmarks, you can add them using a PDF editor such as Adobe Acrobat, or use dokk.ai's Split PDF by page range tool to divide the document manually.

Can I split only at top-level chapters and ignore sub-sections?

Yes. The depth setting lets you choose top-level bookmarks only. Sub-section bookmarks are preserved inside each output file as navigation aids but are not used as additional split points.

Will each output file have its own bookmarks?

Yes. Each output PDF retains the bookmarks that fall within its page range, so readers can still navigate within each section file.

How are the output files named?

Output filenames are derived from the bookmark label. For example, a bookmark labelled 'Chapter 3 Installation' produces a file named 'Chapter 3 Installation.pdf'. Special characters in bookmark labels are sanitised to ensure valid filenames.

What happens to pages before the first bookmark?

Pages that appear before the first bookmark — such as a cover page, table of contents, or preface — are collected into a separate file labelled 'Preface' or '00 Front Matter', so nothing is lost.

Can I split a 500-page PDF by bookmarks?

Yes. There is no page limit for the split operation. Large documents are processed entirely on dokk.ai's servers. The output is a set of individually sized files, each corresponding to one section.

Is the output quality the same as the original?

Yes. The tool reconstructs each section directly from the source PDF's page objects without re-encoding. Text, images, fonts, hyperlinks, and annotations are all preserved at full quality.

Can I recombine selected sections after splitting?

Yes. Use dokk.ai's Merge PDF tool to combine any subset of the split files into a new document. This workflow — split by bookmarks, select sections, merge — is an efficient way to create custom document packages.

What is the difference between Split by Bookmarks and Split by Page Range?

Split by Bookmarks uses the document's semantic structure (chapters, sections) as split points and names files automatically. Split by Page Range requires you to enter specific page numbers manually. Use Split by Bookmarks whenever the document has a proper outline; use page range splitting for documents without bookmarks.

Totes les eines

Divideix per marcadors

Divideix per taula de continguts

1Puja

2Configura

3Processa

Drop file here

PDF, Word, Excel, PowerPoint, images up to 25 MB

Característiques principals

Splits PDF at top-level or nested bookmark positions
Derives output filenames from bookmark labels automatically
Configurable split depth (top-level
second-level
or all levels)
Preserves all content including annotations
fonts
and images in each output file
Retains relevant bookmarks within each split section
Handles documents with hundreds of bookmarks
Outputs individually downloadable files or a ZIP archive
Works with any PDF that contains a document outline
No page number entry required
Secure processing with automatic file deletion
Browser-based with no installation needed

Casos d'ús

Splitting a technical manual into individual chapter PDFs
Distributing textbook sections to students by topic
Extracting individual policy sections from an HR handbook
Separating court transcript sections by witness or exhibit
Publishing component documentation from a master specification PDF
Splitting annual reports into financial and operational sections
Dividing legal contracts by clause group for review
Extracting individual procedures from a multi-procedure quality manual
Separating training modules from a combined course PDF
Producing per-chapter ebooks from a full manuscript

Com s'utilitza

1Upload the PDF that contains bookmarks. The file must have a document outline — visible as the bookmarks panel in Adobe Acrobat or any modern PDF reader.
2Select the bookmark depth: split at top-level bookmarks only, or include second-level headings for finer granularity.
3Optionally review the detected bookmark list to confirm the split points match your expectations.
4Click Process. dokk.ai splits the document at each selected bookmark and names each output file after its bookmark label.
5Download individual section PDFs or a ZIP archive containing all split files.

A 400-page technical manual or annual report is useful as a whole, but when a colleague only needs the 'Installation' chapter or a client only needs the 'Financial Summary' section, sending the entire document is wasteful and inconvenient. Split by Bookmarks solves this by reading the PDF's built-in outline structure — the same hierarchy visible in the bookmarks panel of any PDF reader — and splitting the document at each top-level (or nested) bookmark automatically. PDF bookmarks, also called the document outline, are navigation anchors embedded in the file. When a publisher or author creates a structured document, bookmarks mark the beginning of each chapter, section, or topic. The Split by Bookmarks tool reads these markers and uses them as split points, producing one output file per section with a meaningful filename derived from the bookmark label. You get 'Chapter 1 Introduction.pdf', 'Chapter 2 Installation.pdf', and so on — without ever manually entering page ranges. This tool is invaluable for document management workflows. Legal teams split court transcripts by witness or exhibit. Educators distribute textbook chapters individually to students. Technical writers publish component manuals from a single master source PDF. HR departments split employee handbooks into policy sections for targeted distribution. In all these cases, the alternative — manually noting page numbers and running a split-by-range tool multiple times — is slow, error-prone, and impossible to automate. You can control the depth of splitting. Top-level bookmarks produce broad chapter-level files; including second-level bookmarks produces section-level files. This granularity lets you match the output structure to your distribution needs without over-fragmenting the document. Output files are standard PDFs that open in any reader. They retain all internal links, annotations, images, and embedded fonts from the source. After splitting, use dokk.ai's Merge PDF tool to recombine selected sections, or Bookmarks to inspect and edit the outline of any resulting file. Files are processed securely with TLS encryption and deleted within 60 minutes.

Preguntes freqüents

Seguretat i privadesa

Your PDF is uploaded over TLS encryption and processed on secure servers. All files are automatically deleted within 60 minutes. dokk.ai does not read document content beyond what is required to detect and apply bookmark split points. GDPR compliant.