Frontier and Allegiant are the strongest ultra-low-cost picks for cheap fares if you pack light. Spirit has been through restructuring, so check its current routes and status before booking. Southwest and Breeze are worth comparing when bag fees are added. Compare the total price including bags and seats, not just the base fare.
US budget airlines advertise fares that look almost too good to be true, and they often are — until you add a carry-on, pick a seat, and pay at the airport. The base fare covers only the seat itself, which is why the cheapest ticket isn’t always the cheapest trip.
Here’s how the main low-cost carriers compare, what each is best at, and how to calculate a true price before you click buy. The airline industry changes fast, and some of these carriers have gone through financial restructuring, so check current routes, fees, and policies directly with each airline.
The Main US Budget Airlines Compared
1. Frontier Airlines — Best for Cheap Base Fares
Frontier is known for very low advertised fares and a wide route map, particularly on domestic routes out of large cities. It offers discount programs and sometimes deals on bundles that include bags and seat selection.
Everything beyond the seat, including carry-on bags and seat assignments, costs extra, so compare the total price against competitors. Frontier suits flexible travellers who can pack into a personal item and don’t mind a basic experience.
2. Allegiant Air — Best for Leisure Routes from Smaller Cities
Allegiant focuses on leisure routes, connecting smaller and mid-sized cities to destinations like Florida, Las Vegas, and Arizona, often with nonstop service that larger airlines don’t offer. If you live near one of its bases, it can be the cheapest and most convenient option.
Flights often operate only a few days a week, so a delay or cancellation can leave you stranded longer than on a daily carrier. Check the flight schedule and bag fees before booking.
3. Spirit Airlines — Check Current Status Before Booking
Spirit was long the archetype of the ultra-low-cost model, with rock-bottom fares and a la carte fees. The airline has been through financial restructuring in recent years, with route and capacity changes, so it’s more important than ever to check current schedules and policies.
If you book Spirit, choose flexible options where possible, pack within the personal item size, and have a backup plan for schedule changes.
4. Southwest and Breeze — Worth Comparing
Southwest has traditionally been a value-focused alternative and has been changing its baggage and seating policies, so compare its current fees against the ultra-low-cost carriers. Breeze Airways is a newer low-cost carrier that flies routes between smaller cities, often nonstop.
These airlines can beat the ultra-low-cost carriers on total price once bags and seats are added, so include them in your search rather than assuming the cheapest headline fare wins.
What Budget Airlines Really Cost
| Cost item | Typical treatment | Tip |
|---|---|---|
| Base fare | Seat only | Compare against full-service fares |
| Carry-on bag | Extra fee, often $50–$100+ each way | Fit everything in a personal item |
| Checked bag | Extra fee, price rises at the airport | Pay online, in advance |
| Seat selection | Extra fee | Skip it if not travelling with others |
| Changes and cancellations | Fees or credits | Choose flexible fares for uncertain plans |
How to Book Budget Flights Smartly
- Add up the total price. Include bags, seat selection, and any airport check-in fees before comparing.
- Measure your bag. Personal item size rules are strict, and gate fees are the most expensive way to pay.
- Check the airport. A cheaper flight from a distant airport can cost more once you add transport.
- Avoid tight connections. If a delay happens on a low-cost carrier, rebooking options may be limited.
- Use Google Flights or Skyscanner. Flexible date searches reveal the cheapest days to travel.
Who Should (and Shouldn’t) Fly Budget
- Good fit: solo travellers and couples on short trips who can fit everything into a personal item.
- Good fit: flexible travellers who can shift dates by a day or two to catch the lowest fares.
- Poor fit: families with luggage, since fees for several bags and seats can exceed a standard fare.
- Poor fit: anyone with a tight connection or a must-arrive-on-time event, because rebooking options are limited.
- Poor fit: long-haul or overnight trips where comfort, meals, and entertainment matter.
If in doubt, price out the same trip on a mainstream airline and compare the totals. Sometimes a full-service ticket with bags included turns out to be the cheaper option, and you get a much easier journey for the same money.
Frequently Asked Questions
Are budget airlines safe?
Yes. US airlines of every price tier must meet the same Federal Aviation Administration safety standards. The difference is in service, comfort, and fees, not in the safety requirements.
What is the catch with cheap airline tickets?
The base fare covers only the seat. Bags, seat selection, snacks, and changes cost extra, so a low headline fare can become an average fare once you add what you need.
Can I bring a carry-on on a budget airline for free?
Usually only a small personal item that fits under the seat is included. Larger carry-on bags typically cost extra, so check the size limit and fee before booking.
What if my budget airline flight is cancelled?
Under US rules, airlines must offer a refund for cancelled flights if you choose not to travel. Keep your booking details and check the airline’s policy on rebooking and compensation.
Final Thoughts: Budget airlines can save real money if you pack light and plan carefully, but the cheapest headline price is rarely the final one. Compare the all-in cost, pick the airline that flies your route reliably, and keep a fallback plan for delays.
Airline routes, fees, and policies change often and some carriers have restructured recently — always check current details with the airline before booking.
