PDF tools · Stamp
Number pages in any format, e.g. "Page {n} of {total}". Free without an account; sign in to run it from your app too.
curl https://pdfember.com/api/v1/tools/page-numbers \ -H "Authorization: Bearer $PDFEMBER_KEY" \ -F "files[][email protected]" \ -F "format=Page {n} of {total}" \ -F "position=bottom-right" \ -o out.pdf