Why the pages you keep are not re-rendered#
Removing a page does not mean rebuilding the document — the remaining pages are copied through structurally, keeping their exact fonts, content streams, and embedded resources untouched. Nothing gets rasterized into an image and reassembled, which is the approach that would silently degrade quality. The pages you did not name in the deletion list come out exactly as they went in.
Why deletion order matters internally, even though you never see it#
Deleting page 3 shifts every page after it down by one — page 4 becomes the new page 3. If pages were removed in the order typed (say, "1, 5" removed 1 first, then 5), the second deletion would actually hit what used to be page 6, since everything shifted after the first removal. This tool removes pages from the highest page number to the lowest internally, specifically so each deletion always targets the page you actually meant, regardless of the order you listed them in.
Why removing every single page is blocked#
Asking to remove every page in the document is caught before anything is generated — the result would be a technically valid but completely empty PDF, which is never actually what someone means to produce. This tool treats that as an error rather than silently handing back a file with nothing in it.