Reorder PDF

A PDF's page order is defined by an array of references in the document's page tree — the pages themselves are unaware of their own position. Reordering rewrites that array to reflect the sequence you set, without touching any individual page's content stream, fonts or images, which is why it's fast regardless of document length and why nothing about how a page looks or reads changes, only where it sits.

This is the tool for fixing a scan that came out in the wrong order, moving a cover sheet or table of contents to the front after assembling a document from parts, or rearranging a set of photo pages into a more logical sequence. You only need to move the pages that are out of place — pages left alone keep their position relative to each other.

One thing reordering can't do is update anything printed as part of the page content. If a document already has page numbers baked into its footer text, moving pages around won't renumber those printed digits — they stay exactly as they were on each page, now just appearing in a different sequence. Running Add Page Numbers afterward is the way to get a clean, sequential numbering that matches the new order.