Splitting a PDF is not quite the same as cutting a file in half. A PDF is a document made from pages and the structures that connect them, so choosing pages 1–4 and 5–9 really means creating two new documents from selected parts of the original. That distinction matters. A ten-page PDF can become ten single-page files, two ranges, or several pieces at points you choose. I show those resulting files before you save them so you can see what the split will produce rather than discovering it after the download. The source PDF itself is not changed. I read it in the browser, create the new parts on your device, and let you save them together when you are done. Nothing needs to be uploaded first. I have written more about page ranges, individual-page splitting, and the difference between splitting and extracting pages in Guides.