Frontier Airlines DEN Terminal offers a reasonably priced travel experience. Quick check-in alternatives include online check-in and self-service kiosks. Long layovers might make it seem like there aren't many places to eat and buy, even with the terminal's basic facilities. The boarding process is short, and staff members are happy to answer any queries passengers may have. Although the seating sections might get crowded, Frontier Airlines provides a simple, affordable choice for travelers departing from Denver.