How to Split a PDF File: By Page Range, Size, or Chapter

Key takeaways

• Splitting a PDF is lossless — it copies pages into new files without altering their content, the same way merging does in reverse.
• The right split method depends on what you're splitting for: fixed page ranges, a target file size or page count, or existing bookmarks/chapters.
• Splitting by bookmarks only works if the PDF already has an outline — a table of contents printed on a page isn't the same as a bookmark structure.
• Extracting pages and removing pages are the same operation from opposite directions: keep only what you extract, or keep everything except what you remove.
• Splitting doesn't reduce total file size — the sum of the resulting files is roughly the same size as the original.

Splitting a PDF sounds like a single task, but “split” actually covers a handful of different jobs depending on what you’re trying to do with the result. Pulling one chapter out of a 300-page report is a different operation than breaking a scanned batch into files small enough to email. Here’s how each method works, and which one fits which situation.

What splitting a PDF actually does

Splitting takes one PDF and produces two or more new PDFs, each containing a subset of the original pages. Like merging, it’s a lossless operation — pages are copied into their new files exactly as they were, with no change to text, images, or formatting. Nothing is re-rendered or re-compressed in the process.

One thing splitting does not do is shrink your files. If you split a 20 MB PDF into four 5-page files, those four files still add up to roughly 20 MB combined. If the goal is a smaller file rather than more files, that’s a job for compression, not splitting.

Splitting by page range

This is the most direct method: you specify which pages go into which output file, either as explicit ranges (pages 1–5, 6–10, 11–15) or by manually marking split points.

1. Open a split tool such as Stirling PDF’s split tool.
2. Upload the PDF you want to split.
3. Enter the page ranges or split points you want.
4. Run the split and download the resulting files, usually delivered as a zip if there are more than one or two.

This is the right approach when you know exactly which pages belong together — separating an invoice from an attached receipt, or pulling a signed page out of a longer contract.

Splitting by file size or page count

Sometimes the goal isn’t specific content, it’s a size constraint — an email attachment limit, or an upload cap that rejects anything over a certain number of pages. Auto split by size/count handles this by dividing a PDF into roughly equal chunks based on a target file size or page count, rather than requiring you to work out page numbers by hand.

This is useful for splitting large scanned batches — a stack of scanned documents digitized into one long PDF — into pieces that fit whatever limit you’re working around, without manually counting pages to hit a target.

Splitting by chapters or bookmarks

If a PDF already has a bookmark structure (the outline you see in the sidebar of most PDF readers, distinct from a table of contents printed as a page of text), split by chapters can use that structure directly, creating one file per top-level bookmark automatically.

This only works if the bookmarks actually exist in the file. A PDF that displays a table of contents as regular page content — text and page numbers on a page — doesn’t necessarily have an underlying outline a tool can read; the two are unrelated features that happen to look similar to a reader. If a split-by-chapters tool finds nothing to split on, that’s usually why. In that case, page-range splitting with the chapter start pages is the fallback.

Splitting by sections on a page

A different situation entirely: a single page that itself contains a grid of smaller documents — scanned business cards, four-up flyers, or a sheet of shipping labels. Split by sections divides each page into a grid (2×2, 3×3, etc.) and outputs each cell as its own page, rather than splitting whole pages apart.

Extracting and removing pages: split from either direction

Two related tools solve the same problem from opposite ends:

• Extract pages keeps only the pages you specify and discards the rest — useful when you want a small handful of pages out of a much longer document.
• Remove pages does the reverse: keeps everything except the pages you specify — useful when you’re deleting a few unwanted pages (a blank cover sheet, a duplicate scan) from an otherwise-complete document.

Functionally these produce the same kind of result as a two-way page-range split; which one is faster depends on whether it’s shorter to list the pages you want or the pages you don’t.

Common questions about splitting PDFs

Does splitting reduce file size? No. Splitting only reorganizes existing pages into more files — it doesn’t re-encode images or remove data, so the combined size of the output files is about the same as the original. If you need smaller files, compress each piece afterward.

Will splitting break bookmarks or internal links? Bookmarks and links that point to pages within the same split file are usually preserved; ones pointing to a page that ended up in a different output file won’t resolve, since that page no longer exists in the file it’s referenced from.

What if my PDF doesn’t have bookmarks but I still want to split by chapter? Use page-range splitting instead, entering the page number where each chapter starts. You’ll need to note those page numbers manually first.

Can I undo a split? Splitting itself doesn’t destroy anything — your original file is untouched unless you specifically delete it, and the split-out files can always be merged back together, though not necessarily into byte-identical form.

Picking the right tool without hunting for one each time

Merge and split are opposite operations, but they tend to come up in the same kind of task-switching session — you split a report into chapters, then later need to merge two of those chapters back together for a different reason. PDFPilot keeps both, along with the rest of its catalog, one click away from whatever PDF is already open in your tab, so you’re not re-navigating to a tool site for each half of the job.