Scans inserted in the wrong order, appendices that belong at the end, a cover page that ended up in the middle, or a merged document whose sections need rearranging. Reordering edits the existing PDF - you do not have to split and re-merge anything.
Steps
Open the Reorder PDF Pages tool and upload your PDF
The page thumbnails appear in their current order
Drag each page to its correct position
Click Apply and download the reordered file
Tips
Open the original PDF beside your screen so you can match the target order
For large documents, note down the desired order on paper first, then drag through
If you need to delete pages entirely rather than move them, extract the ones you want with Extract PDF Pages instead
Combine with Rotate PDF if some pages are also sideways