United vs Southwest: Which Airline Is Better in 2026?

Pick Southwest for domestic trips where a canceled flight or a lost bag would hurt most. From January to August 2026 it canceled 1.03% of flights against United’s 1.86%, and mishandled half as many bags per 100 checked.

Pick United if arriving on time matters more (76.1% against 73.1%), if you want a first class or lie-flat seat, or if your trip leaves the Americas. Southwest flies no wide-body jets and nothing beyond Mexico, Central America, the Caribbean and Hawaii.

The two carried almost exactly the same number of passengers in the first half of 2026, 81.5 million on Southwest and 81.4 million on United’s network, so these are rates for airlines of the same size.

The figures come from the DOT’s Air Travel Consumer Reports through the October 2026 edition and the airlines’ own pages as of October 2026. For Southwest against another big carrier, see our Southwest vs Delta comparison.

Cancellations

By our count from the DOT’s monthly tables, Southwest canceled 1.03% of its flights from January to August 2026. United’s network canceled 1.86%, which makes a cancellation about 1.8 times as likely on a United booking.

Both got worse this year. In the first half of 2025 Southwest canceled 0.95% and United 1.35%, and in the first half of 2026 those rates rose to 1.05% and 1.76%.

Part of United’s gap is who flies the plane. United Express partners operated 45.5% of the flights sold under United’s code from January to August and canceled 2.63% of them, while Southwest flies every one of its own flights.

United’s own jets still trail. Its mainline canceled 1.23% of flights over the same eight months, about a fifth more often than Southwest.

Edge: Southwest. It canceled less often than United’s network and United’s mainline alike.

Arriving on time

Here the order flips. United’s network arrived on time on 76.1% of flights from January to August 2026, third among US airline networks behind Alaska and Delta, while Southwest managed 73.1% and ranked fourth.

Southwest started the year best of all, first in January at 82.4%. United beat it in every month after that, and the gap was widest in June, 73.9% against 65.3%.

Over eight months the 3.0-point gap works out at roughly one extra late arrival every 33 flights on Southwest. That is the trade: Southwest more often gets you there, United more often gets you there on time.

Edge: United. A better on-time rate over the year and in seven of the eight months.

Bags, complaints and bumping

Southwest mishandled 0.33 bags per 100 checked from January to August 2026, against 0.71 at United. That is about one lost, damaged or delayed bag in every 300 at Southwest and one in every 140 at United.

Southwest’s bag count has fallen since it started charging for them. It checked 63.6 million bags over those eight months against 77.1 million a year earlier, down 17.6%, yet it still checked more than United’s 53.1 million.

Complaints split the same way. The DOT logged 1,807 complaint cases against Southwest and 6,631 against United over the eight months, or 195 and 646 per 100,000 scheduled flights, so United drew more than three times as many per flight.

Bumping is a tie. In the first half of 2026 United’s network involuntarily denied boarding to 107 passengers and Southwest to 122, out of roughly 81 million each. United asked far more people to give up seats willingly, 23,600 against 4,735.

Edge: Southwest. Fewer mishandled bags and about a third of the complaints per flight, with bumping even.

Bag fees and the cheapest fare

Checked bags now cost the same if you pay ahead. Southwest charges $45 for the first bag and $55 for the second on tickets bought or changed from April 9, 2026. United charges $45 and $55 when you prepay at least 24 hours before departure, or $50 and $60 otherwise, on tickets bought from April 3.

Southwest’s Choice Extra fares and A-List Preferred members get two free bags. A-List members and Southwest credit cardmembers get the first bag free, and A-List pays $35 for the second.

The bigger gap is the cheapest ticket. Southwest’s Basic fare includes a free carry-on and a personal item, and United’s Basic Economy allows only a personal item that fits under the seat, with exceptions for Premier members and eligible United cardmembers.

Changes split the same way. Southwest charges no cancel fee on any fare, Basic included, as long as you cancel at least 10 minutes before departure, though Basic credits expire after 6 months rather than 12.

United’s Basic Economy is non-refundable and cannot be changed, while its standard Economy has no change fee on most itineraries that start in the US.

Edge: Southwest. Bag fees tie, but its cheapest fare keeps the carry-on and can be canceled for credit.

Seats, legroom and premium cabins

Both airlines fly the Boeing 737-800, which makes for a fair seat test. United’s standard economy on the 737-800 has 30 inches of pitch and Economy Plus 34, according to Simple Flying’s July 2025 comparison.

Southwest’s standard pitch on the 737-800 and 737 MAX 8 dropped from 32 inches to 31 to make room for its Extra Legroom rows, The Points Guy reported. That still leaves it an inch ahead of United’s standard economy on the same plane.

Southwest’s open seating ended on January 27, 2026, and seats are now assigned. Basic fares get a seat at check-in, and United also assigns Basic Economy seats.

NerdWallet reports Choice Extra seats carry 5 more inches of pitch on the 737-700. United’s Economy Plus, which we price in United Economy Plus vs Economy, does the same job.

Above economy there is no contest. United sells domestic first class, Premium Plus on long-haul and transcontinental routes and lie-flat Polaris seats, while Southwest has no premium cabin at all.

Edge: Southwest in economy, United above it. An inch more standard legroom on the 737-800, against cabins Southwest does not sell.

Where each one flies

United is the bigger network by far. The DOT counted 236 US airports for United’s network in August 2026 against 106 for Southwest, and United says it serves more than 380 destinations on six continents from hubs in Chicago, Denver, Houston, Los Angeles, Newark, San Francisco and Washington, D.C.

Southwest’s international flights go to Mexico, Central America and the Caribbean. It also sells flights to and between the Hawaiian islands.

In most cities only one of them is a real option. Chicago splits cleanly, with Southwest at Midway and United at O’Hare, a choice we unpack in Midway vs O’Hare.

Denver is where they meet head on: together they flew 83.7% of its August 2026 arrivals. There, United’s network arrived on time 71.9% of the time against 61.7% for Southwest.

Edge: United. More than twice as many US airports, and six continents against Southwest’s corner of the Americas.

Fleet

Southwest ended September 2026 with 803 aircraft, all of them Boeing 737s, and our Southwest fleet count breaks them down by type. It added 20 737 MAX 8s in the third quarter and retired 20 older jets.

United had 1,575 aircraft at the same date, counting its United Express partners. Its mainline fleet stood at 1,066 jets at the end of 2025, averaging 15.3 years, from 19 types.

The split that matters is wide-bodies. United flew 230 of them, including 81 Dreamliners and 22 777-300ERs, while Southwest flies none.

One type keeps Southwest simple: one set of pilots, parts and cabin layout. It also means no lie-flat seats, which United puts on its 787-9s and other long-haul jets.

Edge: United. Wide-bodies and premium cabins Southwest’s all-737 fleet cannot offer.

Wi-Fi and entertainment

Both give free Wi-Fi to loyalty members. Southwest’s is sponsored by T-Mobile and costs $8 per device for non-members on select aircraft, and United’s Starlink service is free for MileagePlus members in every class.

United had Starlink on more than 640 aircraft by October 2026, about half of its flights, and expects 61% by the end of 2026 and the whole fleet by the end of 2027. Southwest expects Starlink on every aircraft by fall 2027.

“We are winning new long-term, brand-loyal United customers because they are trying us for Starlink but staying with us for the industry-leading app, great service, on-board product and technology.”

Scott Kirby, United CEO, third-quarter 2026 results

Entertainment differs more. United streams live TV to Starlink-equipped seatback screens, while Southwest has no seatback screens and streams free movies, TV and live TV to your own device.

Edge: Even. Free member Wi-Fi at both, with United’s seatback screens against Southwest’s bring-your-own-device setup.

Status and the Companion Pass

Southwest’s A-List takes 20 qualifying one-way flights or 35,000 tier qualifying points in 2026. It brings Group 1 boarding, a free first bag and a 25% points bonus.

United’s Premier Silver takes 6,000 Premier Qualifying Points, or 15 flights plus 5,000 points, in 2026, and members earn 1 point per dollar spent on United flights. From 2027 flights stop counting at United, only points, and 1K rises from 28,000 to 32,000.

That gap is easy to price. Twenty one-way fares at $150 each, $3,000 in all, earn A-List on Southwest, while the same $3,000 on United earns 3,000 points, half of what Silver needs.

Southwest changes its program on January 1, 2027. A-List becomes Silver at 35,000 points or 25 flights, A-List Preferred becomes Gold, and a new Platinum tier at 140,000 points or 100 flights brings unlimited Companion Pass trips. On the 2027 rules, 25 fares at $150 still reach Silver for $3,750, well short of United’s $6,000.

The Companion Pass is Southwest’s standout, and it has no United equivalent. Earn it in 2026 with 100 qualifying one-way flights or 135,000 qualifying points, and one chosen person flies with you free of airline charges, paying taxes and fees from $5.60 one-way, through December 31, 2027.

After that, unlimited companion trips belong to Platinum, while a milestone at 95,000 points or 75 flights gives three. United’s pull is where its miles go: Star Alliance partner flights across six continents.

Edge: Southwest. Entry status costs far less in airfare under both years’ rules, and the companion benefit has no United match.

Who should pick which

If you fly from Denver, where both are big, the choice is the one at the top of this page: Southwest for fewer cancellations, United for punctuality and the longer routes. Otherwise book on price and schedule, because a nonstop on either beats a connection on the other.