How to merge PDF files in the right order

Prepare the files you want to combine

For a report pack, collect the cover, main report and appendix as separate PDFs. Open each source first to make sure it is the right version. Password-protected documents need an unprotected copy that you are authorized to edit.

Keep the original documents. Merging copies pages into a new file; document-level bookmarks, attachments and interactive form behavior are not guaranteed to survive. Editing a signed document can also invalidate its signature.

Set the order before merging

Choose all the PDFs, then use Up and Down beside each file. For a cover followed by a report and an appendix, the list should read cover.pdf, report.pdf, appendix.pdf. Remove an accidental selection before processing.

Merge PDF moves whole documents. If page 3 of the appendix belongs inside the report, merge first and use Organize PDF to rearrange the individual pages afterward. Mixed portrait and landscape pages retain their own sizes and orientation.

Download and inspect the result

Select Merge PDFs, wait for the ready message, then select Download PDF. Check the first and last page of each source document in the combined result. The expected page count is the sum of the source page counts.

For a continuous numbering sequence, use Add Page Numbers after the merge. It adds a new footer without removing any numbers already printed in the source files, so check that the two sets do not overlap.

Troubleshooting

The merge button is disabled

Select at least two PDF files. One selected PDF does not need merging. A file with the wrong extension is rejected; export it to PDF first.