BYTETOOLS

Split PDF by Bookmarks

Turn each chapter of a bookmarked PDF into its own file, named after its bookmark, with a choice of which outline level to split on.

Drop a bookmarked PDF here or click to browseChapters become separate files — the split happens in your browser

What is the Split PDF by Bookmarks?

Reports, manuals and scanned books usually carry an outline that already marks where every chapter starts.

  • Reads the real PDF outline and resolves every destination to a page number
  • Split at any outline level, from chapters down to sub-sections
  • Files named after their bookmark titles, with optional numbering
  • Optional front-matter file for pages before the first bookmark
  • Preview of the planned split before anything is written
  • Pages are copied, not re-rendered — no quality loss

How to use the Split PDF by Bookmarks

  1. 1

    Drop a bookmarked PDF onto the upload area — the outline is read straight away.

  2. 2

    Pick the bookmark level to split on: level 1 for chapters, level 2 to go one step deeper.

  3. 3

    Decide whether to keep the pages before the first bookmark and whether to number the file names.

  4. 4

    Check the planned split, which lists each section with its page range.

  5. 5

    Click Split and download the files individually or all at once.

About the Split PDF by Bookmarks

Reports, manuals and scanned books usually carry an outline that already marks where every chapter starts. This tool reads that outline, works out which page each bookmark points at and cuts the document into one file per section — no page numbers to type out by hand.

You choose the level to split on: level 1 gives you one file per chapter, level 2 goes down into the sub-sections. Each output file is named after its bookmark title, optionally numbered so the files sort in reading order, and the pages before the first bookmark can be kept as a separate front-matter file.

Bookmarks are read with pdf.js and the files are written with pdf-lib, all inside your browser. The document is never uploaded, and the split pages are copied rather than re-rendered, so text, links and image quality are exactly as they were.

Frequently asked questions

How do I split a PDF into chapters?

Upload a PDF that has bookmarks, choose level 1 and click Split. Each top-level bookmark starts a new file that runs up to the page before the next bookmark.

My PDF has no bookmarks. What now?

There is nothing to split on. Add an outline first with the Add Bookmarks tool, or split by page ranges with the ordinary Split PDF tool instead.

What happens to the pages before the first bookmark?

By default they are saved as a separate file called “Front matter”. Untick that option and those pages are simply left out of the output.

Two bookmarks point at the same page. What does the tool do?

It keeps the first one and ignores the duplicate, because a section cannot be zero pages long. The merged section keeps the first bookmark's title.

Are the split files identical in quality to the original?

Yes. Pages are copied object by object with pdf-lib, so fonts, images, links and form fields are carried over untouched. Nothing is rasterised or recompressed.

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