Naven
Answers
What age do you have to be to use a messaging app?
Thirteen on most platforms, which is a consequence of US law rather than a judgement about readiness. Services that accept under-13s must obtain verifiable parental consent, which is why most simply refuse.
The Children's Online Privacy Protection Act requires verifiable parental consent before collecting personal information from a child under thirteen. Building that machinery is expensive, so the cheaper route is a terms clause setting the minimum at thirteen and an age box nobody checks.
That does not stop under-13s from using these services; it stops the service from having to think about them.
Naven has a parental consent flow for under-13 accounts, including a printable form, rather than pretending the bracket does not exist.