Which has the bigger carry-on allowance, Frontier or Southwest?

Frontier: 24 × 16 × 10 in (61 × 41 × 25 cm), up to 35 lb (15.9 kg). Southwest: 24 × 16 × 10 in (61 × 41 × 25 cm).

Do Frontier and Southwest include a carry-on on basic economy?

Frontier: The Basic fare includes only a personal item. Add a carry-on when you book; it costs the most at the gate. Southwest: Even the Basic fare includes a carry-on and a personal item. Checked bags cost extra on Basic, Choice and Choice Preferred fares.

Which is more reliable, Frontier or Southwest?

In 2025 Frontier arrived on time 70.7% of the time (1.8% cancelled) and Southwest 77.8% (0.8% cancelled), according to U.S. DOT data.

Which has more legroom, Frontier or Southwest?

Standard economy legroom is about 28 in on Frontier and about 31 in on Southwest. Both sell extra-legroom seats.

Which cancels fewer flights, Frontier or Southwest?

In 2025 Frontier cancelled 1.8% of its flights and Southwest 0.8%, so Southwest had the edge (U.S. DOT data).

Are Frontier and Southwest partners?

They aren't in the same alliance (Frontier: none; Southwest: none), so miles and status generally don't transfer between them.

F9 vs WN · 2026 comparison

Frontier vs Southwest

Frontier wins on a bigger personal item and cheaper checked bags; Southwest wins on a carry-on on its cheapest fare, a more generous carry-on weight limit, more legroom, a better on-time record and fewer cancellations. Here's how they compare on bags, fees, comfort, reliability and loyalty.

Verified Oct 17, 2026By Steven MoHow we check Report a correction

Frontier

Wins 2 categories

A bigger personal item
Cheaper checked bags

Southwest

Wins 5 categories

A carry-on on its cheapest fare
A more generous carry-on weight limit
More legroom
A better on-time record
Fewer cancellations

Quick verdict

Frontier wins on a bigger personal item and cheaper checked bags; Southwest wins on a carry-on on its cheapest fare, a more generous carry-on weight limit, more legroom, a better on-time record and fewer cancellations. Check the cheapest fare's bag rules before you compare prices.

Carry-on size: Frontier: 24 × 16 × 10 in · Southwest: 24 × 16 × 10 in
Carry-on on the cheapest fare: Frontier: Costs extra on basic fares · Southwest: Included on every fare
First checked bag (regular economy): Frontier: $29–$63 · Southwest: $45
Standard economy legroom: Frontier: About 28 in · Southwest: About 31 in
On-time arrivals (2025): Frontier: 70.7% · Southwest: 77.8%

Side by side

	Frontier	Southwest
Bags
Carry-on size	24 × 16 × 10 in	24 × 16 × 10 in
Carry-on on the cheapest fare	Costs extra on basic fares	Included on every fare
Carry-on weight limit	35 lb (15.9 kg)	None published
Personal item	18 × 14 × 8 in	16.25 × 13.5 × 8 in
First checked bag (regular economy)	$29–$63	$45
Comfort
Standard economy legroom	About 28 in	About 31 in
Reliability
On-time arrivals (2025)	70.7%	77.8%
Flights cancelled (2025)	1.8%	0.8%
Network
Alliance	None	None
Loyalty program	FRONTIER Miles	Rapid Rewards
Main hubs	DEN	DEN, LAS, MDW, BWI, DAL

Highlighted values are better for travelers. Fees are for U.S. domestic economy flights; on-time data is 2025 U.S. DOT figures for each airline's own flights.

Bags and fees

Both airlines allow a carry-on up to 24 × 16 × 10 in (61 × 41 × 25 cm).

Frontier charges for it on its cheapest fare, while Southwest includes it on every fare.

Frontier caps carry-ons at 35 lb (15.9 kg); Southwest publishes no limit.

Personal items: 18 × 14 × 8 in (46 × 36 × 20 cm) on Frontier, and 16.25 × 13.5 × 8 in (41 × 34 × 20 cm) on Southwest.

A first checked bag on Frontier costs $29–$63 on all Frontier flights, and a first checked bag on Southwest costs $45 on flights within the U.S. mainland.

Basic economy

Frontier (Basic): The Basic fare includes only a personal item. Add a carry-on when you book; it costs the most at the gate.

Southwest (Basic): Even the Basic fare includes a carry-on and a personal item. Checked bags cost extra on Basic, Choice and Choice Preferred fares.

Seats and Wi-Fi

Frontier gives about 28 in of legroom in standard economy and Southwest about 31 in, an edge for Southwest. Frontier: About 28–29 in. Southwest: 31 in standard since assigned seating began; Extra Legroom rows 34–36 in.

On-time performance

In 2025, Frontier landed 70.7% of its flights on time and cancelled 1.8%; Southwest landed 77.8% on time and cancelled 0.8%. That makes Southwest the more punctual of the two. The figures come from the U.S. DOT and count each airline's own flights, not regional partners.

Loyalty and where they fly

Frontier is not in an alliance and Southwest is not in an alliance.

Loyalty programs: FRONTIER Miles (Frontier) and Rapid Rewards (Southwest).

Frontier's main hubs are Denver (DEN). Southwest's are Denver (DEN), Las Vegas (LAS), Chicago (MDW), Baltimore (BWI), Dallas (DAL). The best choice often comes down to which airline flies nonstop from your airport.

Which should you book?

Choose Frontier if you want…

a bigger personal item
cheaper checked bags
nonstops from DEN

Choose Southwest if you want…

a carry-on on its cheapest fare
a more generous carry-on weight limit
more legroom
a better on-time record
fewer cancellations
nonstops from DEN, LAS, MDW

On a route both fly, the cheaper ticket isn't always the cheaper trip: add the bags you'll actually bring, and check the fare rules before you book.