In short
This tool removes pages from a PDF: a blank page, an unneeded appendix, a page that does not concern the recipient. Click the thumbnails to delete (Shift + click for a range) or type their numbers, for example “2, 5-7”, then download a new PDF; at least one page must remain. The pages you keep are copied exactly as they are, in their order, with the document's title and author; bookmarks are not carried over. The removed pages no longer appear in the file; to hide information on a page you keep, use redaction. If you know instead which pages to keep, “Extract pages” is more direct. The processing happens in your browser and the original stays untouched.