Frontier and Spirit Airlines: What to Know Before You Book a Ultra-Low-Cost Flight

Frontier and Spirit Airlines: The Basics

Frontier and Spirit Airlines are two of the largest ultra-low-cost carriers in the United States, built around stripped-down fares and à la carte pricing. Both airlines sell base tickets that exclude checked bags, carry-ons, seat selection, and in-flight amenities, which can make the final price very different from the one you see at checkout. Understanding how each airline structures its fees and operations is the first step in deciding which one actually saves you money.

Spirit, headquartered in Miramar, Florida, launched its ultra-low-cost model earlier and has long marketed itself as the "Naturally Free" airline, leaning heavily on ancillary revenue. Frontier, based in Denver, re-entered the market after a hiatus and positions itself with a slightly more polished customer experience while keeping base fares aggressively low. Both airlines operate point-to-point networks focused on leisure destinations, with hubs in Florida, the Midwest, and the East Coast.

Fee Structures Compared

The pricing models of Frontier and Spirit are similar in philosophy but differ in execution. Spirit is generally known for charging some of the lowest base fares in the industry, but its add-on fees for bags, seats, and changes can accumulate quickly. Frontier follows a comparable structure, though its fee tiers and bundled options sometimes feel more transparent. The table below summarizes typical fee ranges, though exact amounts vary by route and timing.

Both airlines offer pass programs that bundle bags and other perks, which can be worthwhile for frequent travelers. Spirit's "Free Spirit" program and Frontier's "Discount Den" membership aim to offset the à la carte costs, but the value depends entirely on how often you fly and which add-ons you typically need.

Route Networks and Destinations

Spirit operates a dense network across the eastern U.S., Latin America, and the Caribbean, with major hubs at Fort Lauderdale, Orlando, and Atlantic City. Frontier maintains a strong presence in the Southeast and Midwest, with Denver, Orlando, and Las Vegas serving as key connection points. Both airlines serve many of the same popular leisure routes, including Florida destinations, Cancún, and various Caribbean islands.

Because both carriers are ultra-low-cost, their networks tend to be thinner than those of legacy airlines. You may find fewer daily flights on a given route and less flexibility for rebooking if a flight is canceled. Checking schedule reliability and connection options is especially important when booking multi-city trips on either airline.

Onboard Experience and In-Flight Services

The onboard experience on Frontier and Spirit is intentionally minimal. Seats are narrow with limited legroom, and neither airline includes complimentary food or drinks. Spirit charges for all snacks and beverages, while Frontier has offered a buy-on-board program with modest pricing. Wi-Fi is available on select flights for both airlines, but it is not free and speeds can vary.

Seating policies differ slightly. Spirit assigns seats at check-in or for a fee, with its "Big Front Seat" offering more space at an additional cost. Frontier also charges for preferred seating, and its fare classes determine whether you get a standard or preferred seat. Neither airline is a good fit for travelers who expect complimentary amenities or spacious cabins.

Baggage Policies and Hidden Costs

Baggage is where ultra-low-cost carriers like Frontier and Spirit make or break their value proposition. Both airlines allow one personal item free of charge, but anything larger — a backpack that exceeds dimensions, a carry-on bag, or a checked bag — triggers a fee. These fees are significantly cheaper if purchased online in advance compared to paying at the airport.

• Spirit: One free personal item; carry-on and checked bags must be purchased separately.
• Frontier: One free personal item; carry-on and checked bags are fee-based, with discounts for online prepayment.

Reading the baggage rules carefully before booking can prevent surprise costs at the airport. Both airlines enforce strict size and weight limits, and gate agents may charge higher fees for non-compliant bags.

Safety and Customer Service Reputation

Both Frontier and Spirit operate under FAA regulations and maintain safety records that align with industry standards for U.S. carriers. Customer service experiences are mixed and widely reported in travel forums. Common complaints include difficulty reaching customer support, complex refund processes, and inconsistent communication about schedule changes.

When things go smoothly, the low base fare delivers genuine savings. When issues arise — delays, cancellations, or baggage problems — the lack of built-in flexibility can make resolution more frustrating than with legacy airlines. Checking recent customer reviews for the specific route and time of year you plan to travel can provide a more realistic picture than relying on overall brand ratings.

Which Airline Should You Choose?

The right choice between Frontier and Spirit depends on your priorities. If your trip is simple, you travel light, and you are comfortable booking add-ons in advance, either airline can offer a very low-cost option. Spirit may edge out on base fare price for some routes, while Frontier sometimes provides a slightly more consistent experience on Midwest and Mountain West corridors.

For families or travelers with multiple bags, the total cost after fees can rival or exceed legacy carriers, so calculating the full price — including bags, seat selection, and any extras — is essential before booking. Consider whether the savings on the base fare justify the trade-offs in flexibility, comfort, and customer service support.