How to Merge, Split and Reorder PDF Pages

Application forms, invoices, scanned receipts, contracts with attachments — sooner or later you need several PDFs to become one, or one big PDF to become several. Here is how to do it cleanly.

When to merge PDFs

• Applications with a single-file upload slot. Visa, university and job applications often want ID, proof of address and a letter in one PDF.
• Expense reports. One PDF of receipts is easier to attach and approve than twelve.
• Sending a package to a client. A cover page, the proposal and the terms in one file feel more professional.
• Archiving. A month of invoices as a single file is simpler to store and search.

How to merge without surprises

1. Name the files so they sort in the order you want (01-cover, 02-id, 03-proof). Drag-and-drop tools usually add files in the order selected, so this saves rearranging later.
2. Add them all, then check the order before you create the merged file. Reordering is trivial before merging and awkward afterwards.
3. Watch mixed page sizes. A phone photo turned into a PDF page may come out a different size to an A4 letter. Both will display, but printing may scale them differently. Converting the photos with our JPG to PDF tool first, at a fixed page size, avoids this.
4. Check the file size. Merging adds sizes together. If the result is too big, compress it afterwards — see how to reduce a PDF's size.

When to split a PDF

• An upload limit is smaller than the whole document.
• You only want to share a few pages, such as one chapter or the signature page, rather than the entire file.
• A scanned batch contains several separate documents that need filing individually.
• You need to extract a page to fill out or sign separately.

Ways to split

There are three common approaches. Pick by what you are trying to achieve (our Split PDF does the first two: pick pages from thumbnails, or export every page separately):

• By page range. "Pages 3–7" gives you exactly the chapter or form you need. Use this most of the time.
• Every page separately. Handy for scanned batches where each page is its own document.
• Into equal chunks. Useful for staying under a size limit; split a 60-page file into three 20-page files.

Remember that page numbers in the file are counted from the first physical page, which may differ from the printed numbers in the document's footer if there is a cover or front matter.

Pitfalls worth knowing

• Bookmarks and links. Internal links and a table of contents may stop working after splitting, since their targets could be in another file.
• Form fields. Fillable forms sometimes lose interactivity when combined. Fill in the forms first, or flatten them.
• Encrypted PDFs. Password-protected files must be unlocked before they can be merged or split.
• Orientation. A landscape page in a portrait document is fine; it just needs rotating in the viewer if it was scanned sideways.

Keeping sensitive documents private

The documents people merge are exactly the ones they'd rather not hand over: passports, bank statements, contracts. Web tools that upload to a server put a copy of those files on someone else's machine, at least temporarily. Merge PDF and Split PDF here use pdf-lib inside your browser, so the files are read into your device's memory and written back to you without any network transfer. You can even switch off your internet connection after the page loads and they keep working.

Frequently asked questions

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