The CNA exam is administered by a state-approved vendor in most states. Some states choose companies such as Prometric or Headmaster while other states choose educational institutions such as state-accredited colleges to administer and grade the nurse aide exam. None of these contractors allow individuals to take the certification exam online. When you register for the test, you pick an exam site from an approved list and that is the location where the skills and the written portions of the exam take place. It is all done under the supervision of qualified personnel. This protocol ensures that only qualified individuals pass the examination and become certified nurse aides. You may contact your state's nurse aide registry to find out who administers the exam in your state.