Privacy, in plain terms
Your invitation data is never uploaded. The builder runs entirely in your browser and encodes your details into the link on your own device. When a guest opens the link, the part of the address after the # is read by their browser only — it is not sent to this site’s server, and we could not read your wedding details even if we wanted to.
Replies go directly between your guests and the reply page you chose (your form, WhatsApp or email). Vowlio is not in that path and receives no copy.
Like most websites, the hosting provider may keep standard technical logs (such as the pages requested and timestamps) for security and operation. Those logs do not contain your invitation contents, which never leave the # part of your link.
One practical caution: anyone who has your invitation link can open it. Treat it like the paper card — send it to your guests, rather than posting it publicly, if your venues and dates are not for the whole internet.