Passport renewal may be done in two ways: by mail or in person.
It is not feasible to renew a US passport fully online,
while part of the passport renewal paperwork can be completed online.
You may renew your passport by mail, which eliminates the need for an in-person visit.
However, in order to finish the procedure by mail, you must satisfy a few conditions;
in rare cases, you may be forced to renew your passport in person.