How do I combine or split PDF files?

This is one of the most common everyday document tasks and the one most often done by uploading a private file to an unknown website. Every operating system can do it locally, and the local method is usually faster as well.

Safety

Step by step

1. Use Preview on a Mac for everything.Open the PDF, show the thumbnail sidebar, and you can drag pages to reorder, select and delete them, and drag pages from one open PDF into another to merge. Then save as a new file.
2. Drag whole documents to merge on a Mac.With both PDFs open in Preview and thumbnails showing, drag the thumbnails from one sidebar into the other at the position you want. Save with a new name so the originals survive.
3. Split on Windows by printing a page range.Open the PDF in Edge, choose Print, select Microsoft Print to PDF, and set the page range. Saving that produces a new PDF of just those pages. No extra software needed.
4. Merge on Windows with an offline tool.Windows has no built-in merge. A free, well-known offline application does it in seconds and, unlike a website, the document never leaves the machine.
5. Do it on a phone if that is where the files are.The Files app on iPhone can combine PDFs by selecting several and choosing create PDF. Most Android file managers and PDF viewers have an equivalent.
6. Reorder pages before merging, not after.Getting each document in the right order first makes the merge trivial. Reordering forty pages in a combined document is considerably more work.
7. Rotate pages that scanned sideways.Preview and most viewers rotate individual pages and save the rotation. A merged document with one page on its side looks careless and takes seconds to fix.
8. Check the file size afterwards.Merged scans get large quickly. Most tools offer a reduce-file-size or optimise option, which matters if it is going by email.
9. Always save as a new file.Never overwrite the original until you have checked the result. Page operations are easy to get slightly wrong and hard to undo once saved.
10. Open the result before sending it.Check the page order, the orientation and that nothing is missing. A merged document is exactly the sort of thing that goes out with two pages transposed.
11. Use an offline tool for anything sensitive.Bank statements, identity documents, contracts, medical letters. This is the whole reason for preferring the local method.

Tips

• Name the output file meaningfully before sending. 'merged.pdf' arriving in someone's inbox tells them nothing.
• If you do this regularly, a free offline PDF application is worth installing once — it is faster than the print-to-PDF workaround and keeps everything local.
• Scanning several documents into one PDF at the point of scanning avoids merging entirely.

Common mistakes

• Uploading a bank statement to a free online PDF tool — The document is transmitted to and stored on someone else's server. The tools on your own computer do the same job without it leaving the machine.
• Overwriting the original — Page operations are easy to get subtly wrong, and without the original there is nothing to go back to. Always save as a new file.

If it doesn't work

Questions people ask