Scanners export one file per sheet. Merge them in one run instead of re-scanning, and use Reverse if your scanner fed pages in reverse order.
In practice: (1) Name files 01, 02, 03… before uploading so the list order is obvious. (2) Compress after merging to shrink the combined file once. (3) Add page numbers afterwards if the document will be printed.
Frequently asked questions
How do I keep the original scan order?
Upload in filename order, then drag any stray file into place before clicking merge.
Will merging reduce quality?
No. Merging copies pages without re-encoding, so quality is identical to the sources.
Do it in the full tool
Open Merge PDF for all options, or jump straight to another step below.