Pages end up in the wrong order more often than you would think — a scanner that fed a stack backwards, a merge done in the wrong sequence, an appendix that belongs at the front, or a form where the signature page was captured last.
The list is the whole document
This is the important thing to understand and it differs from the other page tools. You are not describing a change — you are writing out the new document, page by page. Every page you want must appear in the list, and the order you write is the order you get.
That has two consequences worth knowing. Pages you leave out are dropped, so "3,1,2" on a five-page document gives you a three-page document. And repeating a number duplicates that page, so "1,2,1" is legitimate and produces a copy of page 1 at the end.
Writing the order
- Separate numbers with commas or spaces — "3,1,2" and "3 1 2" are the same.
- Every number must be a real page in the document; anything out of range is rejected with a message rather than silently ignored.
- Unlike the page-selection boxes elsewhere on the site, ranges are not accepted here, because a range cannot express order.
- For a long document, this becomes tedious — if you only want the order flipped, use the page reverser instead.
Why ranges are deliberately not allowed
It would be easy to accept "5-1" and treat it as counting down. It would also be ambiguous: elsewhere on this site ranges are unordered selections, where "5-1" and "1-5" mean the same set of pages. Allowing the same syntax to mean two different things depending on the tool is exactly how someone ends up with a document they did not expect. Here, order is explicit and every page is written out.
The pages themselves are untouched
Reordering copies page objects into a new sequence. Nothing is re-rendered or re-compressed, so text stays selectable, images keep their original data and the document prints exactly as before — just in a different order. A duplicated page is a genuine second reference to the same content rather than a second copy, so duplicating pages costs almost nothing in file size.
Bookmarks do not survive, and neither do form field interactions. Encrypted PDFs are refused with an explanation. Everything runs in this tab.
Write the list somewhere else first
For anything longer than about ten pages, type the order into a text editor before pasting it in. It is easy to lose your place halfway through a long list, and a page silently omitted is much harder to spot in the result than a page in the wrong position. Counting the numbers you have written against the page count is a quick check worth doing.