Smallpdf's Organize PDF workflow displays page thumbnails so individual pages can be duplicated and dragged into the required order. The tool works in a browser, and the guide notes that password protection or editing restrictions can prevent reorganization.

Duplicate Selected PDF Pages Without Copying the Whole File

Check the finished document after duplication, especially links, bookmarks, form fields and signatures. Repeated pages can also increase file size when they contain large scans or images, so verify both functionality and the intended page sequence.