Split PDF

Cut a PDF into separate files — take a chapter out of a report, or break a long scan into the documents it should have been. The cutting happens in this browser, on this computer: the file is not uploaded, because burrow has no server that could receive it.

Saying where to cut

Give the pages you want to cut after. A cut goes in the gap that follows a page, so on a ten-page document 3, 7 makes three files: pages 1-3, 4-7 and 8-10. Cutting after page 10 is refused, because the part after it would have no pages in it.

A range cuts after each page in it, so 1-9 on a ten-page document gives every page its own file — and the Cut after every page button types that for you. It types it into the box rather than switching to a mode, so you can see what it asked for and change one cut afterwards.

The page shows the files you will get before you run anything. That is there because “after” is the part people read past, and showing the result is more honest than asking you to take our word for how it was read.

Each file is named for the pages inside it — report-pages-04-07.pdf — and the numbers are padded so that ten parts sort in order rather than 1, 10, 2. The name is not a label we attach afterwards: it is the pages that file contains.

There are no page pictures yet. Choosing where to cut means knowing page numbers, and for splitting that is a real limitation rather than an oversight — you often want to cut where a chapter starts, which is something you find by looking. Showing pages means rendering them, and rendering a long document needs a memory ceiling burrow does not have yet. It is being built; until it is, this page does not pretend to offer it.

What happens to large files

Everything is held in this browser tab's memory, so the practical limit is what your device can spare rather than an upload size. burrow refuses a file larger than 512 MB before it opens it, and a document of more than 10,000 pages before it cuts any of it — so an oversized job is refused rather than failing part way through.

What that does not save you from, said here rather than discovered: a very large document that is under both limits can still make the tab slow while it runs, and on a phone the browser may stop the tab entirely. That is the device's memory ceiling, reached inside the PDF engine where nothing can intervene.

Nothing is handed to you until every part has been made and checked. A split that fails on the ninth of ten parts gives you nothing at all, deliberately: the point of splitting is that the parts add up to the document you started with, and nine files out of ten do not add up to anything. If it stops part way, you still have your original and no half-finished set to sort through.

What is kept, and what is not

Each part contains its pages exactly as they were — their contents, their size and their annotations. Links keep working when they point inside the same part, and links to a page in a different part are removed rather than left to go nowhere. Web links are kept.

Form fields keep their appearance but are no longer fillable. What makes a field a field is recorded for the document as a whole, not on the page, so it cannot come with one part — and carrying it would carry the names and the values typed on pages that part does not contain. Bookmarks and attached files are left out for the same reason: they describe the whole document, and copying them into every part would put the names of pages you did not include into files you did.

A document that uses layers cannot be split here at all. Whether a layer is hidden is recorded for the document as a whole, so burrow has no way to find out — and a hidden layer that arrived visible would be worse than a refusal.

A file that is encrypted, damaged, or not a PDF is refused. So is a cut that would produce an empty file — cutting after the last page, or after the same page twice.