How to Merge PDF Files in the Right Order (Without Mixing Up Pages)

Combining PDFs takes a few seconds. The part that goes wrong is the order. The appendix lands before the cover letter, the signature page ends up first, and nobody notices until the document has already been sent. A small amount of care before you press the button avoids all of it.

How the order works

Merge PDF joins your files in the order they appear in its list, top to bottom. Each file keeps its own pages in their original sequence, so file one's pages come first, then file two's, and so on. The list is numbered, which makes it easy to read the final order at a glance.

1. Drop in two or more PDFs. Each one is added to the list.
2. Read the numbered list and compare it to the order you want.
3. Use the up arrow next to a file to move it one place higher. Use the X to remove a file you added by mistake.
4. Press Merge PDFs, then use the Download button to save the combined file.

Moving a file down

There's only an up arrow, no down arrow, so the trick is to think the other way around. To push file two below file three, move file three up one place instead. Same result, one click.

Two quirks are worth knowing. Files you add later are placed at the end of the list, not where you might expect. And if you change the order after merging, the earlier result is cleared, so you need to press Merge PDFs again before downloading.

Set the order before you upload

The easiest way to get the order right is to fix it in the file names first. Add a number to the start of each name: 01-cover-letter, 02-application-form, 03-references. When you select several files at once, your computer will often hand them over in name order, which means the list comes out right from the start. Often isn't always, though, so still read the numbered list before merging.

When pages need to interleave

Merging works on whole files. It can't slip one page from file A into the middle of file B. If you need that, split the second file first. Say you want a signed page from file A to sit between page 3 and page 4 of file B:

1. Use Split PDF on file B to extract pages 1-3 into one file, then extract the rest into another.
2. Do the same to pull the signed page out of file A if it's part of a longer document.
3. Merge the pieces in this order: first part of B, the signed page, rest of B.

It's a few extra steps, but it works with the tools you already have. The guide on extracting pages from a PDF walks through the page-range format.

Check the result before you send it

• Scroll through the merged file once. You're checking that each section starts where you expect, not reading every page.
• Look for sideways pages. A page that was fine on its own can look wrong in a combined document, and Rotate PDF fixes it quickly.
• Number the pages last. If you want a continuous sequence, merge first and then use PDF Page Numbering, otherwise each file restarts at 1.
• Keep your source files. Merging creates a new document and leaves the originals alone, so you can always redo it in a different order.

What merging doesn't carry over

Merging copies the pages themselves. Extras attached to the original files, such as bookmarks or interactive form fields, may not make it into the combined document, so check anything like that in the result. Each file also needs to be under 50 MB, and very large combinations depend on your device's memory because the work happens in your browser.