Three ways to split
Ranges: type “1-3, 5, 8-10” to get one PDF per range, or tick “merge ranges into one file” to extract just those pages into a single PDF. Every page: each page becomes its own PDF. Every N pages: cut a long scan into chunks of, say, 10 pages.
Lossless extraction
Pages are copied, not re-rendered, so fonts, text selection and image quality are identical to the original. Click a thumbnail to add that page to the range box.