How to merge PDF files and keep the pages in the right order

Merging is the most requested PDF job, usually because a form asks for one file and you have five. The mechanics are simple. The problems are almost always about order and size.

The steps

1. Open Merge PDF and add every file.
2. Drag the files into the order you want, or use the arrow buttons. Files merge top to bottom, so the first file in the list becomes page 1.
3. Press Merge and download the result.

Nothing is uploaded, so a 90 MB folder of scans merges as fast as your computer can read it.

Three problems people hit

Scanned pages in reverse. Sheet feeders often produce the last page first. Merge as usual, then run Reverse PDF Pages on the result, or fix the order first with Reorder PDF Pages.

Some pages sideways. Rotation is stored per page, so a merged file can mix portrait and landscape. Rotate PDF takes a page range, so you can turn only pages 4 to 9 without touching the rest.

The merged file is too big to upload. Merging adds up: five 2 MB scans give you a 10 MB file. Run Compress PDF afterwards, or use one of the fixed targets such as Compress PDF to 1 MB when a portal states a limit.

What merging does not keep

Page content, links and form fields inside each page survive. Bookmarks from the original documents are not combined, and if two files both contain form fields with the same name, filling one can fill the other. If that matters, flatten the forms before merging.

If one of your files is password protected, remove the password first with Remove PDF Password. A locked file cannot be read by any tool, including this one, until it is unlocked.