Learn the page-range format for PDF extraction, combine ranges with individual pages and avoid invalid or reversed selections.
Use file positions rather than printed labels
Split PDF counts pages from the beginning of the file. Position 1 is the first PDF page, even when that page is an unnumbered cover. A printed label such as page 10 may therefore appear at a different position in the actual file.
Check the source in a viewer before entering a range. If the section you want spans file positions 4 through 9, use those positions rather than copying the printed numbers from the document footer.
Combine single pages and ascending ranges
Enter a single position to keep one page, such as 2. Use a hyphen for a continuous section, such as 4-9. Separate multiple selections with commas: 2, 4-9, 12 keeps page two, then pages four through nine, then page twelve.
The range endpoints are included. A selection of 4-6 therefore produces three pages, not two. The tool preserves the order of your selections while removing repeated positions. Spaces around commas or a hyphen are accepted, but other notation is not part of this input format.
Correct invalid input before exporting
Use positive whole numbers within the displayed page count. A reversed range such as 9-4 is rejected. If you need a different order, list the individual positions or arrange ascending ranges in your preferred sequence.
Empty entries, letters and decimal page numbers also cause an error. For example, 1,,3 contains a blank entry between commas. Fix the selection rather than expecting the tool to guess which pages you meant.
Verify the output against your selection
Generate and download the PDF, then count the resulting pages. Review the transitions where one range ends and another begins. A syntactically valid range can still select the wrong chapter if you confused printed labels with file positions. Keep the source until the extracted document has been checked and is ready to use.