When booking a flight, U.S. travelers can often take their pick from three major legacy airlines: Delta Air Lines, United Airlines and American Airlines. But in the battle of Delta, United or American, which one is best?

To choose, consider five factors: where each flies, their credit card offerings, their loyalty programs, overall fees and the in-flight experience. Here’s a closer look at how these three airlines compare.

Where they're based and where they fly

Winner for accessibility: United

United offers the most international destinations and countries flown to of these three airlines, and it’s practically tied with American for the most destinations overall.

Delta, United and American each operate flights to hundreds of domestic destinations and international flights to dozens of countries. So the right airline for you will likely depend on your proximity to a hub. Except for the major markets of New York, Los Angeles and Chicago, each airline focuses its hubs in different cities.

Delta

As the old saying goes, "Whether you go to heaven or hell, you have to change planes in Atlanta." Atlanta-based Delta Air Lines operates a network of about 300 destinations in over 50 countries across six continents.

Delta's U.S. hubs and key markets include:

Atlanta.

Boston.

Detroit.

Los Angeles.

Minneapolis-St. Paul.

New York-John F. Kennedy.

New York-LaGuardia.

Salt Lake City.

Seattle.

United

Chicago-based United Airlines flies to around 215 U.S. destinations in addition to roughly 130 international destinations across 70 countries covering Asia, Europe, India, Oceania, South America and parts of Africa.

United's airport hubs can be found in:

Chicago-O'Hare.

Denver.

Guam.

Houston-Intercontinental.

Los Angeles.

Newark.

San Francisco.

Washington-Dulles.

American

American Airlines bases its operations in Dallas-Fort Worth and flies to almost 350 destinations across 60-plus countries on five continents. American focuses on flights to the Caribbean, Europe, South America and connecting its Oneworld partners to destinations in Asia and Oceania.

American Airlines' hubs are found in:

Charlotte.

Chicago-O’Hare.

Dallas-Fort Worth.

Los Angeles.

Miami.

New York-John F. Kennedy.

New York-LaGuardia.

Philadelphia.

Phoenix.

Washington-National.

Travel credit card availability

Winner for airline credit card: Delta

NerdWallet thinks a lot about the question of which airline offers the best credit card. Our roundup of the top airline credit cards on the market includes three Delta credit cards, two American cards and one United card — making Delta the winner if you’re considering a travel credit card that’s co-branded with a specific airline.

Delta, United and American each offer a wide range of consumer and small-business credit cards. Each has a no-annual-fee card, a midtier card with a few perks — like free checked bags — and a premium card that includes lounge access.

Here are the details for each.

Delta

Delta offers four consumer and three small-business credit cards — all of which are issued by American Express. Annual fees range between $0 and $550 and perks range from earning 2x miles on restaurants up to Delta Sky Club access. Terms apply.

Delta SkyMiles® Blue American Express Card ($0 annual fee). Earn 10,000 bonus miles after you spend $1,000 in purchases on your new Card in your first 6 months. Terms Apply.

Delta SkyMiles® Gold American Express Card ($0 introductory annual fee for the first year, then $99 annual fee). Earn 40,000 bonus miles after you spend $2,000 in purchases on your new Card in your first 6 months. Terms Apply.

Delta SkyMiles® Platinum American Express Card ($250 annual fee). Earn 50,000 bonus miles after you spend $3,000 in purchases on your new Card in your first 6 months. Terms Apply.

Delta SkyMiles® Reserve American Express Card ($550 annual fee). Earn 60,000 bonus miles after you spend $5,000 in purchases on your new Card in your first 6 months. Terms Apply.

Delta SkyMiles® Gold Business American Express Card (​​$0 intro for the first year, then $99). Earn 50,000 Bonus Miles after spending $2,000 in purchases on your new Card in your first 3 months of Card Membership. Terms Apply.

Delta SkyMiles® Platinum Business American Express Card ($250 annual fee). Earn 60,000 Bonus Miles after spending $3,000 in purchases on your new Card in your first 3 months of Card Membership. Terms Apply.

Delta SkyMiles® Reserve Business American Express Card ($550 annual fee). Earn 70,000 Bonus Miles after spending $5,000 in purchases on your new Card in your first 3 months of Card Membership. Terms Apply.

United

United offers four personal credit cards and two business credit cards through Chase. Annual fees range from $0 to $525 and perks vary from earning 2x points at gas stations to United Club membership.

United Gateway℠ Card ($0 annual fee). Earn 30,000 bonus miles after you spend $1,000 on purchases in the first 3 months your account is open.

United℠ Explorer Card ($0 intro for the first year, then $95). Earn 60,000 bonus miles after you spend $3,000 on purchases in the first 3 months your account is open.

United Quest℠ Card ($250 annual fee). Earn 70,000 bonus miles and 500 Premier qualifying points after you spend $4,000 on purchases in the first 3 months your account is open.

United Club℠ Infinite Card ($525 annual fee). Earn 90,000 bonus miles after you spend $5,000 on purchases in the first 3 months from account opening.

United℠ Business Card ($0 intro for the first year, then $99). Earn 50,000 bonus miles after you spend $5,000 on purchases in the first 3 months your account is open.

United Club℠ Business Card ($450 annual fee). Earn 50,000 bonus miles after spending $5,000 on purchases in the first 3 months your account is open.

American

American Airlines offers four AAdvantage credit cards through Citi and one AAdvantage Aviator credit card through Barclays. Annual fees range from $0 to $595 and perks vary from earning 2x points on groceries to a full Admirals Club membership.

American Airlines AAdvantage® MileUp® ($0 annual fee). Earn 15,000 American Airlines AAdvantage® bonus miles after making $500 in purchases within the first 3 months of account opening.

Citi® / AAdvantage® Platinum Select® World Elite Mastercard® ($0 intro for the first year, then $99). Earn 50,000 American Airlines AAdvantage® bonus miles after spending $2,500 in purchases within the first 3 months of account opening.

Citi® / AAdvantage® Executive World Elite Mastercard® ($595 annual fee). Earn 70,000 American Airlines AAdvantage® bonus miles after spending $7,000 within the first 3 months of account opening.

CitiBusiness® / AAdvantage® Platinum Select® Mastercard® ($0 intro for the first year, then $99). Earn 65,000 American Airlines AAdvantage® bonus miles after spending $4,000 in purchases within the first 4 months of account opening.

AAdvantage® Aviator® Red World Elite Mastercard® ($99 annual fee). Earn 60,000 AAdvantage® bonus miles after making your first purchase and paying the $99 annual fee in full, both within the first 90 days.

Airline loyalty programs

Winner for ease of earning and redeeming miles: American

The overall value of American Airlines’ miles gives American the edge over United. Even better, American still publishes an award chart, and you can easily redeem airline miles for award flights with American and its partners online.

On all three airlines, you'll earn miles based on the dollars you spend on airfare. But when it’s time to redeem those miles, the three carriers differ significantly.

Delta SkyMiles

(Editor's note: Big changes are coming to Delta's SkyMiles program in 2024, including how members can earn elite status. The carrier will also be cutting back Sky Club lounge access. Read more on these upcoming changes here.)

General Delta SkyMiles members earn 5 SkyMiles per dollar spent on airfare — unless booking basic economy (the only fare that does not earn SkyMiles). You'll earn even more miles if you have Delta Medallion elite status, up to a total of 11 miles per dollar. Delta doesn't offer as many opportunities to earn miles through partners, but there are still 20 ways to earn SkyMiles.

Delta award flight prices vary based on demand, costing anywhere from 3,000 miles up to almost half a million miles one way. Prices also vary when you redeem SkyMiles to fly one of Delta’s partner airlines, so you’ll need to search your preferred route to find out how many miles you’ll need.

NerdWallet analysis finds that Delta SkyMiles are worth 1.2 cents per mile for economy class flights.

United MileagePlus

United MileagePlus members earn a base of 5 miles per dollar spent on airfare. Premier elite members earn a status bonus of between 2 and 6 miles, for a total of up to 11 miles per dollar spent. However, there are plenty of other ways to earn United miles.

Members can redeem miles on United or any of its dozens of Star Alliance partners. United miles are worth just 1.2 cents each in economy.

American AAdvantage

AAdvantage members earn 5 miles per eligible dollar spent on airfare, with elite members getting up to 11 miles per dollar spent. There is no limit to the number of miles you can earn per ticket. In addition to spending on airfare, we've discovered a total of 36 ways to earn AAdvantage miles.

You can redeem AAdvantage miles to over 1,000 destinations, and you can redeem miles on most partner airlines right on AA's website. Unlike Delta and United, American publishes an award chart showing how many AAdvantage miles you need for an award flight on American or any of its dozens of partner airlines. American miles are worth around 1.7 cents each for economy class flights.

Extra fees

Winner for lowest fees: Delta

Nowadays, the airfare that you pay — or the miles you redeem — is usually just part of the cost of your trip. Fees will likely increase the total cost.

NerdWallet did a deep-dive investigation of all of the major carriers and their fees. Most airlines charge a similar amount in fees — with the exception of low-cost carriers Spirit and Frontier — but Delta and American are slightly cheaper. These two airlines charge an average of $30 in fees for a one-way flight, whereas United charges a bit more at $35 per trip.

Delta

Checked bag fees: For domestic flights, Delta charges $30 for the first checked bag. Travelers with an eligible credit card, elite status or active military status may be able to avoid this charge.

Seat assignment fees: On basic economy tickets, you'll need to pay a seat assignment fee to avoid getting a randomly assigned seat at check-in. All other fares allow free seat selection.

Change fees: Delta has eliminated change fees for trips originating in Africa, Canada, Europe, the Caribbean and the United States. However, basic economy fares are nonchangeable.

United

Checked bag fees: United doesn't publish baggage fees. Instead, you need to use United's checked bag calculator to see how much you'll pay. Checked bags for domestic flights currently start at $30 prepaid or $35 if you pay within 24 hours of departure.

Carry-on bag fees: United stands alone among the three airlines in not allowing basic economy passengers to bring a carry-on bag. If you book a basic economy fare, you'll need to check any full-size carry-on bags — unless you can use elite status or a credit card to board early. If you get caught at the gate trying to board with a full-size carry-on bag, you'll need to pay the checked bag fee plus an extra $25. Travelers flying to South America or across the Atlantic or Pacific are allowed a carry-on bag with a basic economy ticket.

Seat assignment fees: United basic economy passengers need to pay to select or change their seat. All other fare types come with free seat selection.

Change fees: On United, you won't pay a fee to change or cancel flights within Mexico, the Caribbean or the U.S., or on other international itineraries originating in the U.S. However, basic economy fares cannot be changed.

American

Checked bag fees: American publishes a complicated grid of checked bag fees. You'll pay $30 for a first checked bag on domestic routes — unless you have elite status or an eligible credit card.

Seat assignment fees: All American fares come with free standard seat selection except basic economy. Travelers flying basic economy can pay a fee to select a seat anytime after booking.

Change fees: Like United and Delta, American has generally eliminated change fees for all fare types. You can change your flight fee-free as long as your flight doesn’t start in Australia, New Zealand, Spain or the U.K. Like the other airlines, most basic economy tickets are nonchangeable, with the exception of flights originating in most European countries — which you can change for a fee.

In-flight experience

Winner of the sky: Delta

Besides offering recently updated and comfortable cabins, Delta outranks United and American in our analysis of the best in-flight entertainment offerings. Delta’s recent introduction of free Wi-Fi for all passengers on most domestic routes — with an expansion to the entire fleet by the end of 2024 — pushes this airline to the top of this category.

Delta

Delta owns many aircraft that are more than 20 years old, but you probably couldn't tell by looking at the cabin. Delta has retrofitted many of its older planes with new seats and in-flight entertainment screens. On international flights in economy, Delta has introduced premium meals, hot towel service and alcoholic drinks like Bellinis.

United

United announced in June 2021 that it would install seatback entertainment, additional premium seats, larger overhead bins and high-speed Wi-Fi. However, you still need to wait a few years to see these onboard improvements.

American

American is taking a lower-cost strategy with its in-flight product. It has tightened seat pitch and removed in-flight entertainment screens from almost all of its domestic fleet. The upside of these "Project Oasis" retrofits: bigger overhead bins, power outlets at every seat and high-speed Wi-Fi — for a fee.

If you’re trying to choose between Delta, United and American

Choose Delta: The airline wins in three of our five categories, making it the overall winner of the battle between major U.S. airlines. Delta excels in providing a consistently good onboard experience, understandable fees and an extensive range of credit cards that provide a good fit for every type of traveler. However, United offers travelers more destinations and American’s loyalty program is easier to use.

Take an even closer look in our head-to-head comparison of Delta versus United, or check out our analysis of American versus Delta for another take.

The right airline for you depends on your specific situation. American or United may be a better fit if you're located in — or frequently travel to — one of their hubs.

The information related to the CitiBusiness® / AAdvantage® Platinum Select® Mastercard® and United Club℠ Business Card has been collected by NerdWallet and has not been reviewed or provided by the issuer or provider of this product or service.