Why does splitting by size create more parts than expected?

Each part has to carry its own copy of shared resources such as fonts and images, so the parts add up to more than the original. The tool saves every part to measure its real size so none exceeds the limit; a single page that is larger than the limit on its own becomes its own file, marked “oversize”.

Can I split by chapter if the PDF has no bookmarks?

Splitting by bookmarks needs the PDF to have an outline. If it doesn’t, add bookmarks with our bookmark editor first, or use Text match with a pattern such as “Chapter \d+” to cut at each chapter heading.

How are blank separator pages detected?

Each page is rendered at low resolution and the share of dark pixels (ignoring the outer 5%) is measured; pages below the threshold with no text at all count as blank. Blank sheets in scans often have specks, so raise the threshold slightly if some are missed.

Are my files uploaded?

No. Reading, detection and creating the new PDFs all happen in your browser, so it is safe for contracts, invoices and other sensitive files.

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🪓Split PDF by Bookmarks, File Size, Text or Blank Pages

Basic splitters only cut by page ranges, but real documents often need smarter rules. This tool offers six. By bookmarks: one file per chapter named after the bookmark title, using only top-level bookmarks or deeper levels, with the relevant bookmarks kept inside each file. By file size: set a maximum in MB and the tool actually saves each part to measure it, packing as many pages as fit, which is ideal for email attachments and upload limits. Every N pages: fixed-size chunks. Odd/even pages: one file of odd pages and one of even pages, handy for double-sided scans. Blank separator pages: when batch scanning with a blank sheet between documents, the file is cut at every blank sheet and the sheets are dropped. Text match: a new file starts at every page containing a keyword such as “Invoice No.” or “Chapter” (regular expressions supported), named after the line that matched. Except for the size and blank-page modes, you see the plan first (file names, pages and counts), then download everything as a numbered ZIP. Everything runs locally in your browser.

Free · No sign-up · Runs in your browserLast updated: 2026-10-26

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How to use Advanced PDF Splitter

1Upload the PDF you want to split
2Choose a split mode (bookmarks, file size, every N pages, odd/even, blank pages or text match), set its options and review the planned files
3Click Split & download; multiple files are bundled into a ZIP

FAQ

Why does splitting by size create more parts than expected?: Each part has to carry its own copy of shared resources such as fonts and images, so the parts add up to more than the original. The tool saves every part to measure its real size so none exceeds the limit; a single page that is larger than the limit on its own becomes its own file, marked “oversize”.
Can I split by chapter if the PDF has no bookmarks?: Splitting by bookmarks needs the PDF to have an outline. If it doesn’t, add bookmarks with our bookmark editor first, or use Text match with a pattern such as “Chapter \d+” to cut at each chapter heading.
How are blank separator pages detected?: Each page is rendered at low resolution and the share of dark pixels (ignoring the outer 5%) is measured; pages below the threshold with no text at all count as blank. Blank sheets in scans often have specks, so raise the threshold slightly if some are missed.
Are my files uploaded?: No. Reading, detection and creating the new PDFs all happen in your browser, so it is safe for contracts, invoices and other sensitive files.