Are provisional applications published or made available to the public?

No, provisional applications are not published or made available to the public by the USPTO. The MPEP 201.04 clearly states:

A provisional application is not subject to publication and is not subject to examination other than to review for national security implications.

This means that the contents of a provisional application remain confidential unless and until a corresponding non-provisional application is published or a patent is issued. This confidentiality can be advantageous for inventors who want to maintain secrecy while securing an early filing date.

For more information on provisional application, visit: provisional application.