Delta vs United vs American vs Southwest with a baby: Which US airline is best for families? (2026)
Key facts
Short answer: all 6 major US airlines let under-2s fly free on your lap domestically and check 1 stroller + 1 car seat free. United and JetBlue win for guaranteed free family seating, pre-boarding for under-2s, and a free diaper bag on all fares; Southwest wins for huge 24 × 16 × 10 in bins and Family Boarding; and note American Airlines' 20 lb limit for carrying a stroller on board.
In Europe, parents debate Ryanair vs easyJet. In the United States, the big family question is Delta vs United vs American Airlines vs Southwest (plus JetBlue and Alaska): while all of them let infants under 2 fly free on your lap domestically and check one stroller and one car seat free, their rules on gate-check weight limits, free diaper bags, guaranteed adjacent family seating, and early family boarding are wildly different.
For example: did you know that American Airlines bans gate-checking any stroller over 20 lbs (9 kg), while United Airlines gate-checks even folding stroller wagons for free? Or that United, American, JetBlue, and Alaska guarantee free adjacent family seating even on Basic Economy, while Delta still relies on gate-agent assistance if you book Basic Economy?
Here is the complete 2026 head-to-head comparison of the major US airlines for flying with a baby or toddler, sourced directly from each airline's official contract of carriage and family policy page (checked October 2026).
Master comparison table: 6 major US airlines with a baby (2026)
| Feature / Rule | Delta Air Lines | United Airlines | American Airlines | Southwest Airlines | JetBlue | Alaska Airlines |
|---|---|---|---|---|---|---|
| Domestic Lap Infant Fare (under 2) | FREE | FREE | FREE | FREE | FREE | FREE |
| International Lap Infant Fare | 10% of adult fare + taxes | 10% of adult fare + taxes | 10% of adult fare + taxes | Taxes/fees only | 10% of adult fare + taxes | Taxes/fees (or 10% int'l) |
| Minimum Newborn Age (no doctor letter) | 7 days old | 7 days old | 7 days old (2–6 days with medical form) | 14 days old | 3 days old | 7 days old (or check carrier) |
| Free Stroller & Car Seat Allowance | 1 stroller + 1 car seat FREE | 1 stroller (or folding wagon!) + 1 car seat FREE | 1 stroller + 1 car seat FREE | 1 stroller + 1 car seat FREE (+ 2 free checked bags!) | 1 stroller + 1 car seat FREE | 1 stroller + 1 car seat FREE |
| Gate-Check Stroller Weight Limit | No weight limit | Small collapsible strollers & folding wagons at gate | STRICT 20 lb (9 kg) limit at gate! (>20 lbs must check at counter) | No weight limit | No weight limit | No weight limit (planeside valet!) |
| Free Diaper Bag in Cabin (for lap infant)? | Breast pump bag is free; diaper bag counts toward carry-on/personal item unless ticketed | YES — 1 free diaper bag + breast pump on top of carry-on (even Basic Economy!) | YES — 1 free diaper bag + breast pump on top of carry-on | Generous carry-on + personal item + breast pump | YES — 1 free diaper bag on all fares (even Blue Basic!) | Diaper bag counts as carry-on/personal item; breast pump free |
| Carry-On Overhead Bin Sizer | 22 × 14 × 9 in (56 × 35 × 23 cm) | 22 × 14 × 9 in (56 × 35 × 22 cm) | 22 × 14 × 9 in (56 × 36 × 23 cm) | 24 × 16 × 10 in (61 × 41 × 25 cm — largest in US!) | 22 × 14 × 9 in (55.8 × 35.5 × 22.8 cm) | 22 × 14 × 9 in (56 × 35 × 22 cm) |
| Free Guaranteed Adjacent Family Seating? | Not automated on Basic Economy (call or ask gate agent) | YES — Free for under-12s (even on Basic Economy, plus free switch if full!) | YES — Free for under-15s (even on Basic Economy) | Family Boarding between Groups A & B (ages 6 & under) | YES — Free for 13 & under (even on Blue Basic) | YES — Free for 13 & under (even on Saver fares) |
| Family Pre-Boarding Timing | Early Boarding for families with car seats & strollers (after Diamond/First) | Pre-boarding for families with children 2 and younger! | Pre-boarding for families with children under 2! | Between Group A & Group B (children 6 & under) | Pre-boarding for families with children 2 and under | Pre-boarding for families with children under 2 |
| Widebody Bassinets (SkyCots) | SkyCot up to 20 lbs (9 kg) & 26 in | Bassinet up to 22 lbs (10 kg) on 767/777/787 | Bassinet up to 20 lbs (9 kg) on 777/787 | None (all-737 fleet) | None | None |
1. Winner for Family Seating & Gear Policies: United Airlines
If you are comparing the "Big Three" US legacy carriers, United Airlines currently has the most parent-friendly written policies from booking to boarding:
- Free Adjacent Family Seating Tool: If you travel with a child under 12, United's seat map automatically unlocks adjacent standard economy seats for free at booking — even on Basic Economy tickets! If a flight is so full that adjacent seats aren't available, United allows you to switch to another flight to the same destination with open adjacent seats at zero fare difference.
- Extra Diaper Bag + Breast Pump + Stroller/Wagon: Even on a Basic Economy ticket (where regular passengers don't get a full carry-on), United explicitly allows a diaper bag, a breast pump and cooler of milk, a stroller or folding wagon, and a car seat completely free.
- Pre-boarding for age 2 and under: Families with children aged 2 and under board during Pre-boarding (before Group 1), giving you first pick of overhead bin space for a Stokke YOYO3 or Joolz Aer+ and unhurried time to install a Cosco Scenera NEXT car seat.
2. Winner for Short-Haul Value, Open Seats & Overhead Bins: Southwest Airlines
For domestic US hops to Florida, California, Hawaii, Texas, or Colorado, Southwest Airlines offers three massive family perks:
- Largest overhead bins in the US (
24 × 16 × 10 in/61 × 41 × 25 cm): While Delta, United, and American enforce a narrow 14-inch carry-on width limit on paper, Southwest's 16-inch-wide limit means compact strollers like the Bugaboo Butterfly 2, Joolz Aer+, and Stokke YOYO3 fit on paper with inches to spare! (Test them in our Cabin Size Stroller Checker.) - Family Boarding between Groups A and B: Up to two adults travelling with a child aged 6 or younger board right after Group A — guaranteeing your whole family sits together with empty overhead bins right above your row.
- The free open-seat car seat trick: If your Southwest flight isn't 100% full, ask the gate agent before boarding if there are empty seats. When space permits, Southwest lets you bring your FAA-approved car seat on board for your lap infant to sit in at $0 extra cost!
3. What to watch out for on American Airlines: The 20 lb gate-check stroller limit
American Airlines is generous on family seating (guaranteeing adjacent seats for children under 15 at no cost) and allows a free diaper bag and pre-boarding for under-2s. However, American enforces one rule that catches thousands of parents off guard at the airport:
- Strollers weighing MORE than 20 lbs (9 kg) CANNOT be gate-checked on American Airlines! They must be checked at the main ticket counter before security (still free, but you lose your stroller for the entire walk through the terminal and during layovers).
- How to beat the 20 lb rule: Bring a travel stroller under 20 lbs — such as the Joie Pact Lite (11.8 lbs), Joolz Aer+ (13.2 lbs), Stokke YOYO3 (13.6 lbs), Bugaboo Butterfly 2 (16.1 lbs), or UPPAbaby Minu V2 (16.9 lbs) — all of which can be wheeled right down the jet bridge on American Airlines!
4. Delta Air Lines, JetBlue & Alaska Airlines: Where each shines
- Delta Air Lines: Best for on-time operational reliability, seatback entertainment screens on almost every mainline jet (lifesaving for toddlers!), and SkyCot bassinets on long-haul widebodies. Just avoid booking Delta Basic Economy with a toddler so you can pick adjacent seats immediately at booking.
- JetBlue: Widest average economy seats (17.8 to 18.4 in) and most legroom in coach, free diaper bag on every fare, free Wi-Fi and seatback screens, and guaranteed adjacent family seating for children 13 and under.
- Alaska Airlines: Best for West Coast, Pacific Northwest, and Hawaii trips, with planeside stroller valet at the gate and guaranteed adjacent seating for children 13 and under even on Saver tickets.
Related airline & flight gear guides
- Best Travel Strollers for Flying & Disney (Inches & Lbs)
- Best Car Seats for Airplanes in the US
- FAA Car Seat Rules on Planes & TSA Breast Milk Rules
- Cabin Size Stroller & Pushchair Checker (16 Airlines)
- All 19 Airline Baby & Stroller Guides
FAQs
Which US airline is best for flying with a baby?
United Airlines and JetBlue win for guaranteed free family seating, pre-boarding for age 2 and under, and a free cabin diaper bag on all fares. Southwest Airlines wins for generous overhead bin limits (24 × 16 × 10 in), two free checked bags per ticket, and letting lap infants use an FAA car seat in an empty seat for free when flights aren't full.
Does Delta, United or American charge for strollers or car seats?
No! Delta, United, American, Southwest, JetBlue, Alaska, and Air Canada all check one stroller and one car seat free per child. Just remember that American Airlines requires strollers over 20 lbs (9 kg) to be checked at the ticket counter rather than at the gate.
Which US airlines guarantee families sit together for free?
United Airlines (under 12), American Airlines (under 15), JetBlue (13 and under), Alaska Airlines (13 and under), and Air Canada (under 14) all guarantee adjacent family seating with an accompanying adult at no extra fee, even on Basic Economy / Saver fares. Southwest provides Family Boarding between Groups A and B so families can sit together in open seating.
Sources
- US Department of Transportation (DOT): Airline Family Seating Dashboard (checked October 2026)
- Delta Air Lines: Children & Infant Travel (checked October 2026)
- United Airlines: Traveling with Children & Family Seating (checked October 2026)
- American Airlines: Traveling with Children (checked October 2026)
- Southwest Airlines: Flying with Babies & Toddlers (checked October 2026)
Last checked and updated: · Kiddieko · How we check facts
