Drop in a PDF, type the pages you want to keep (for example 1,4,7-9), and download a fresh PDF with just those pages, in that order. Everything happens in your browser, your file is never uploaded, so it is safe for confidential drawings. No signup, no email, no watermark.
Click the pages you want to keep. Selected pages get an amber ring and a check. The new PDF is built in page order, top to bottom, left to right.