The Unbundled Model: What You're Actually Paying
Spirit and Frontier both use ultra-low-cost carrier (ULCC) models: the base fare is stripped of everything, and you pay separately for bags, seat selection, food, and any flexibility. The base fare comparison is meaningless without accounting for every add-on you'll actually need.
Change Fee Comparison
| Timing Before Departure | Spirit Fee | Frontier Fee |
|---|---|---|
| 60+ days | $69/person | $39/person |
| 14–59 days | $99/person | $59/person |
| Under 14 days | $119/person | $99/person |
| With protection add-on | Flight Flex: Free (1x) | WORKS: Free (unlimited) |
| 24-hour cancel | Free (any fare) | Free (any fare) |
Verdict: Frontier wins on change fees — lower at every timing window. The WORKS bundle offers unlimited changes vs. Spirit's single-use Flight Flex.
Seat Upgrade Comparison
Spirit's Big Front Seat: Equivalent of a business seat — wider, more legroom, at the front. Costs $12–60 per segment. No traditional cabin classes above this. Standard seat selection: $5–25 per seat.
Frontier's UpFront Plus: Front-of-cabin placement with extra legroom. Costs $15–40 per segment. Frontier also has Stretch Seating at exit rows ($10–30 extra). Neither matches Spirit's Big Front Seat for pure comfort.
Verdict: Spirit wins on premium seating — the Big Front Seat provides noticeably more comfort than Frontier's options.
Cancellation Comparison
Both: 24-hour full refund on any fare. After that, both issue 90-day travel credits (not cash) for standard fare cancellations. Spirit credits are non-transferable. Frontier credits are also non-transferable except via the WORKS bundle.
Frontier with WORKS wins here — the bundle includes a full cash refund option, which Spirit has no equivalent for.
The Real Total Cost Test
Before choosing either carrier, add up your actual needs: base fare + carry-on + seat selection + change protection (if needed). Then compare to a standard economy fare on Delta, United, or American for the same route. Budget carriers are genuinely cheaper for travelers who:
- Travel with only a personal item (no carry-on or checked bag)
- Don't need any flexibility in their plans
- Don't care about seat selection
- Are flying routes where budget carriers have much lower base fares
For most travelers with a carry-on and any flexibility needs, the gap narrows significantly — and occasionally disappears entirely.