How to reorder pages in a PDF
Rearranging pages is built into Preview on a Mac, but missing on Windows, iPhone and Android. Here is what works on Windows, Mac, iPhone and Android.
On a Mac with Preview
Preview's sidebar (View, Thumbnails) shows every page, and dragging a thumbnail to a new position moves it, while selecting a page and pressing delete removes it. Save the file afterward. This is one of the few built-in PDF viewers that supports rearranging pages directly.
On Windows
Edge's PDF reader can delete a page (right-click a thumbnail in the sidebar, Delete) but has no way to drag pages into a new order; reordering isn't supported in the built-in viewer at all.
On an iPhone or Android
Neither platform's Files app or default PDF viewer supports reordering or deleting individual pages from an existing PDF. This is a genuine gap on mobile, not a hidden setting.
A page thumbnail view that works in your browser
Stayput's reorder & delete pages tool shows every page as a thumbnail, lets you drag them into a new order and remove the ones you don't need, then saves the result, directly in the browser without uploading the document. It works the same way on a phone or a computer, unlike Preview's drag-and-drop which is Mac-only.
Questions
Can I delete a page from a PDF without deleting others?
Yes, both Preview's sidebar and a dedicated page-management tool let you select and remove one page while leaving the rest of the document intact.
Can I reorder pages on an iPhone or Android?
Not with the built-in Files app or default PDF viewer on either platform; a browser-based tool that shows page thumbnails works the same way on mobile as on a computer.
Does reordering pages change their content?
No, it only changes the position of each page in the document; the text and images on each page stay exactly as they were.
Can I undo a page deletion after saving?
Once saved, the deleted page is gone from that file; keep a copy of the original PDF beforehand if there is any chance you'll need the removed page again.