I have five files with unwanted pages. Should I delete them before merging or after?

Why deleting after the merge is quicker

Five files, cleaned one at a time, means opening Delete PDF pages five times, selecting and downloading five times, then gathering the five results in Merge PDFs. Merge first and you open the delete tool once on the merged file, see every page in one grid, and pick out all the unwanted pages in a single pass.

The one catch: page numbers shift

The terms page was page 4 inside file three, but it becomes page 11 after merging, because 4 pages from file one and 3 from file two now come before it. If you know the unwanted pages by their number in each file, you have to add an offset for every file, and that is where mistakes creep in. The practical answer is to go by the thumbnails, not the numbers: a blank page or a repeated cover stands out clearly in the grid.

When to delete before merging

• You know the numbers precisely inside each file, for example because every file is a report from the same system and its last page is always a disclaimer.
• The merged file would be very large, close to the tested limit of 500 pages and 100 MB, so working on smaller files is easier on your device.
• Each file needs a check by a different person before it is combined, so each person cleans their own file.
• You will also use the cleaned files on their own, not only in the merged file.

What stays the same whichever order you choose

Both tools build a new file from pages, and bookmarks, interactive fields and document metadata come across in neither. So you gain nothing on that front by switching the order. Page numbers printed inside the content do not change either way, so if each file was numbered from 1, the final file will carry those old numbers.

One last tip: put the files in the final order you want inside the merge tool before merging, since ordering files there is easier than moving pages afterwards.