How hidden the page itself is
While you are building, it is hidden completely: an unpublished event is not visible to guests in any form, so a draft page has no address that anyone can find. That quiet phase is genuinely private, and it is worth using โ draft the evening, check what a visitor sees, and only then let the page exist.
After publishing, the page is reachable but not announced. There is no directory of webinar pages and no listing your session appears in; the URL travels exactly as far as the messages you send. So when hosts ask how to keep a webinar out of strangers' way, the useful answer is a ladder of choices rather than one switch: share quietly, gate the form, cap the seats, and keep the door handle in the confirmation email where it started.