Southwest vs Delta: Which Airline Is Better in 2026?

Pick Southwest if you fly domestic routes from an airport where it dominates, such as Baltimore, Nashville or Las Vegas, and a canceled flight would hurt you more than a late one. It canceled 1.05% of flights in the first half of 2026, about half Delta’s mainline rate of 2.09%. Pick Delta if arriving on time matters most (80.26% against Southwest’s 74.76%) or if your trip leaves North America.

Southwest’s old selling points have mostly gone. It ended open seating for flights from January 27, 2026, and its checked bag fees are now the same as Delta’s at $45 and $55.

The figures here come from the Department of Transportation’s Air Travel Consumer Report published in August 2026, covering January to June 2026, plus each airline’s own fee and loyalty pages as of October 2026. For the other big carriers, see our comparison of Delta vs United vs American and our ranking of the best airlines to fly in the US.

Arriving on time

Southwest arrived on time on 74.76% of its flights between January and June 2026, fourth among the nine US carriers in the DOT’s ranking and down from 78.91% a year earlier. Delta’s network managed 79.33%, second only to Alaska, and its own mainline flights reached 80.26%.

A 5.5-point gap sounds small until you spread it over a year. On 40 flights, Southwest would deliver about 10 late arrivals against about 8 on Delta mainline.

The latest month is starker. In June 2026 Delta’s network arrived on time 80.8% of the time, first among the carriers in the DOT’s June table. Southwest managed 65.3%, last of the eight. If you want to know what happens behind the gate on a late day, our explainer on why flights get delayed covers it.

Edge: Delta. It was more punctual over the half year and far more punctual in the latest month.

Cancellations

Here the order flips. Southwest canceled 1.05% of flights between January and June 2026, the second-best rate of the nine carriers behind Allegiant’s 0.90%.

Delta’s mainline canceled 2.09%, and its network, with regional partners included, 2.35%. Per 1,000 flights that is about 10.5 canceled at Southwest and 20.9 at Delta mainline.

The gap is newer than the headline suggests. In the first half of 2025 Southwest canceled 0.95% and Delta’s network 1.22%, with its mainline at 0.99%.

Delta’s rate has since roughly doubled, though June 2026 was calmer, at 1.4% for its network against 0.6% for Southwest. Check the latest monthly DOT report before treating the gap as permanent.

One Delta detail matters when you book. Regional partners flew 37.6% of its scheduled flights (306,479 of 816,084) and canceled 2.77% of them, so a flight operated by Delta Connection carries more risk than the logo suggests.

Edge: Southwest. It canceled about half as often as Delta’s mainline, and Southwest has no regional partner flights to dilute the figure.

Bag fees: the old Southwest edge is gone

Southwest ended its free checked bags for reservations booked and ticketed on or after May 28, 2025, at $35 for the first bag and $45 for the second. It raised both by $10 for reservations ticketed or changed on or after April 9, 2026.

Delta made the same $10 increase a day earlier, for flights booked on or after April 8, 2026. Both airlines now charge $45 for the first bag and $55 for the second.

Each still waives the fee for some travelers. Southwest gives two free bags with Choice Extra fares and A-List Preferred status, and one free bag to A-List members and Rapid Rewards credit cardmembers. Delta gives its first bag free to Medallion members and eligible Delta SkyMiles American Express cardmembers.

Carry-ons differ slightly. Southwest allows a free carry-on up to 24 x 16 x 10 inches, which adds up to 50 linear inches, plus a personal item. Delta’s carry-on limit is 45 linear inches combined.

Passengers noticed. Southwest handled 46.4 million checked bags between January and June 2026 against 59.0 million a year earlier, a drop of 21.5%, while its scheduled flights barely moved (686,476 against 687,727). Delta’s volume rose 2.1% over the same period.

Southwest still handles bags slightly better. It mishandled 0.32 bags per 100 checked, third best of the nine carriers, against 0.37 for Delta’s network and 0.38 for its mainline.

Edge: Even on fees, Southwest on mishandled bags. The prices match, and the 0.05-per-100 lead in bag handling is small.

Changing or canceling a ticket

Southwest charges no cancellation fee on any fare type. The catch is the “10 minute rule”: you must cancel at least 10 minutes before the flight’s original departure or you can forfeit the fare.

What you get back depends on the fare. Basic fares are non-refundable apart from the 24-hour rule, and their flight credits expire after six months, while credits from Choice, Choice Preferred and Choice Extra fares last 12 months. A Basic fare can be changed only by upgrading it, and the other fares pay just the fare difference.

Delta charges no change fee on Main Classic, Extra or Refundable tickets that start in the US or Canada. A Basic ticket can usually be changed or canceled, but a fee comes off its value, and the amount depends on the route, so check the fee table when you book.

Edge: Southwest. A canceled Basic ticket returns as credit with no fee deducted, which Delta’s Basic fare does not match.

Seats and boarding

Southwest’s open seating is over. For flights from January 27, 2026, seats are assigned, and boarding runs in eight groups instead of the old A, B and C.

Choice, Choice Preferred and Choice Extra fares pick a seat at booking, while Basic fares are assigned one at check-in. Boarding order follows fare, status, seat type and cabin position: A-List Preferred members board before Group 1, A-List members in Group 1, and cardmembers no later than Group 5.

On legroom, Delta publishes a number and Southwest mostly does not. Delta lists 31 inches of pitch in Main and 33 to 34 inches in Comfort on its 737-800. Southwest says its Extra Legroom seats, at the front of the cabin and in the exit rows, have “a few more inches” than standard, and it does not state a standard pitch on the pages we checked.

That is why “are Delta seats smaller than Southwest’s?” has no clean answer. Check the seat map for your own flight.

Edge: Even. Both now assign seats and sell extra legroom, and neither has a published advantage you can rely on.

Where each one flies

This usually settles the choice, and it settles it by your home airport. In June 2026 the DOT counted 211 US airports for Delta’s network and 108 for Southwest.

Delta says it flies up to 5,500 daily flights to more than 300 destinations on six continents. Southwest’s international page lists Mexico, Central America and the Caribbean.

Southwest carries nearly all arrivals at Chicago Midway and most at Baltimore/Washington. Delta holds Atlanta, Minneapolis-St. Paul and Detroit the same way.

The two overlap at seven of those 30 airports, where each carries at least 10% of arrivals: Austin, Nashville, Orlando, Tampa, Fort Lauderdale, Washington National and Los Angeles. Southwest recorded no June arrivals at JFK, Newark, Dallas/Fort Worth or Houston Intercontinental.

The fleets are built differently. Southwest flew 803 aircraft as of June 2026, all Boeing 737s: 288 737-700s, 192 737-800s and 323 737 MAX 8s. Delta’s mainline fleet was 1,004 aircraft across 17 types as of July 2026, from the Airbus A220 to the A350-900 on long-haul routes.

One type means one set of pilots, parts and cabin layout. It also means Southwest cannot offer a lie-flat seat or a transatlantic flight, which Delta can.

Edge: Delta. It serves about twice as many US airports and, on its own pages, reaches six continents where Southwest lists three international regions.

Complaints and bumping

The DOT logged 1,249 complaint cases against Southwest between January and June 2026 and 4,534 against Delta. Delta schedules more flights, so we divided: 182 complaints per 100,000 flights at Southwest and 556 at Delta, about three times as many per flight.

Delta’s cases can include complaints about flights its regional partners operated, because passengers complain against the brand on the ticket. Even so, the gap is wide.

Bumping runs the other way. Between April and June 2026 Delta’s network reported zero involuntary denied boardings among 49.7 million enplaned passengers, while Southwest reported 58 among 44.4 million. Both rates are tiny, and 3,065 Southwest passengers volunteered to give up seats against 27,806 at Delta.

Edge: Southwest. It draws about a third as many complaints per flight, though Delta bumped fewer passengers.

Loyalty: Companion Pass or Medallion

Southwest’s signature benefit is the Companion Pass. Fly 100 qualifying one-way flights or earn 135,000 qualifying points in a calendar year, and one chosen person flies with you free of airline charges, paying only taxes and fees from $5.60 one-way, for the rest of that year and all of the next.

Its A-List tier is closer to hand, at 20 qualifying flights or 35,000 tier qualifying points a year. It brings Group 1 boarding, a free first checked bag and a 25% points bonus.

Delta’s Medallion ladder is built on spend. Silver Medallion takes $5,000 in Medallion Qualification Dollars, which count base fare and carrier-imposed surcharges on Delta-marketed flights in Main Cabin or above but not bag fees or taxes. Diamond takes $28,000 for status earned in 2026.

Edge: Southwest, for two people who fly together. A Companion Pass flies the second person for a few dollars each way. For solo travelers, compare what each ladder asks against what you spend.

Who should pick which

If no row describes you, book on price and schedule. We did not compare fares, which vary by route and date, and a nonstop on either airline will usually beat a connection on the other.