Yes, you can bring a carry-on on Southwest if it fits 24 x 16 x 10 inches and you also keep to one personal item.
Southwest keeps carry-on rules simple: one bag up top, one smaller item under the seat. That’s the whole deal. If you size your bag right and pack for security screening, you avoid the last-minute “gate check” shuffle and keep your essentials close.
| Item You Bring | Southwest Rule In Plain Terms | Counts Toward Your Two Items? |
|---|---|---|
| Carry-on bag (overhead) | Max 24 in x 16 in x 10 in, with wheels and handles included | Yes |
| Personal item (under seat) | Must fit fully under the seat in front of you | Yes |
| Garment bag | Allowed as your carry-on if it stays within the same size limit | Yes |
| Pet carrier | Treated as one item of your allowance; it stows under the seat | Yes (carry-on or personal item) |
| Stroller | Usually gate-checked; keep it accessible at boarding | No (handled separately) |
| Child car seat | Can go on board for a ticketed child; it must be FAA-approved | No (when used for the child’s seat) |
| Medical or assistive device | Allowed and typically not counted when it qualifies as a device | No (when it qualifies) |
| Musical instrument | Must fit in the bin or under the seat, or it needs its own seat | Yes (unless it has its own seat) |
Can You Bring A Carry-On On Southwest?
Yes. Southwest lets each ticketed passenger bring one carry-on bag plus one personal item at no extra charge. Southwest sets the carry-on maximum at 24 x 16 x 10 inches, and it measures wheels, handles, and attachments as part of the total size.
Southwest posts this on its Carryon and Personal Item Policy page. If you want the “is it free?” answer in writing, Southwest also lists the carry-on allowance on its Optional Travel Charges page.
Bringing A Carry-On On Southwest With Size Limits That Match The Sizer
Many bags are sold as “carry-on size,” yet small details can push them over the line. A case labeled “22-inch” can still fail if the wheels stick out or a hard front pocket bulges when packed.
Do a quick fit check at home. Stand the bag upright and measure height including wheels. Then measure width and depth at the widest points. If any side is over 24 x 16 x 10 inches, plan to switch bags or check it.
What Southwest Calls A Carry-on Bag
A carry-on bag is the larger of your two items. It goes in the overhead bin. Typical choices are a roller suitcase, duffel, or garment bag. Southwest doesn’t publish a carry-on weight limit, yet you still need to lift it into the bin on your own.
What Southwest Calls A Personal Item
Your personal item is the smaller piece that stays under the seat. Common picks are a purse, laptop bag, slim backpack, or camera bag. Southwest’s policy language focuses on fit under the seat, not a single fixed measurement, since under-seat space varies by aircraft and seat row.
Soft bags travel smoother here. If your under-seat space is tight, you can compress a soft backpack in a way a rigid case can’t.
How Southwest Counts Your Two Items At The Gate
At boarding, staff watch two things: how many pieces you carry and whether your larger bag fits the sizer. If you show up with a carry-on, a personal item, and a third loose item, you’ll be asked to combine or check something.
Loose add-ons are the usual trap. A shopping bag from the terminal, a neck pillow clipped to your backpack, or a big coat you don’t wear can become a “third item” in seconds. Before you step into line, pack loose pieces inside one of your two bags.
Items That Commonly Count As A Third Piece
- Shopping bag that won’t fit inside your backpack
- Bulky tech case carried separately
- Garment bag carried outside your suitcase
- Loose pillow or blanket strapped to a bag
Security Rules That Affect What Goes In Your Carry-on
Southwest’s size rules and airport security rules aren’t the same. Your bag can fit the sizer and still get stopped at screening if you pack restricted items. The most common issue is liquids and gels.
Liquids, Toiletries, And The 3-1-1 Setup
For U.S. flights, follow TSA’s Liquids, Aerosols, and Gels rule: containers up to 3.4 oz (100 ml) go into one quart-size bag, one bag per passenger. If your shampoo bottle is bigger, put it in checked baggage or leave it at home.
Pack the liquids bag near the top of your carry-on or personal item so you can pull it out fast if your lane asks for it.
Foods That Behave Like Liquids
Peanut butter, hummus, yogurt, jam, and creamy dips often get treated like liquids at screening. If it can be smeared or poured, treat it like a liquid and keep it under 3.4 oz in your carry-on.
Power Banks And Spare Batteries
Keep power banks and spare lithium batteries in your carry-on. Put them where you can reach them during screening, and cover exposed terminals so nothing can short out in your bag.
Choosing A Carry-on That Fits Southwest Bins
If you fly Southwest often, the simplest move is to use a bag built around 24 x 16 x 10 inches. Still, luggage labels can mislead because brands may advertise “class sizes” instead of full exterior dimensions.
Soft Duffel Vs Hard Shell
Soft duffels are forgiving. You can compress them if a bin is tight or rotate them to fit. Hard shells protect better, yet they don’t flex when a corner or wheel sticks out. If you’re near the limit, soft often causes fewer headaches.
Wheels, Handles, And Packed Pockets
Southwest includes wheels and handles in the measurement. Stiff front pockets can also add depth once packed. Measure your bag while it’s packed the way you actually travel, not empty on the floor.
Boarding Details That Change Your Overhead Space Odds
Southwest uses open seating, so overhead space fills as people board. If you board late, the front bins may already be full. That doesn’t change the allowance, yet it can push your bag toward a gate check if there’s no room nearby.
Two habits help: keep your under-seat bag slim and easy to slide in, and pack your carry-on so you can lift and place it fast. Quick loading keeps lines moving and keeps attention off your bag.
Traveling With Kids, Pets, Or Gear
Family travel adds extra pieces fast, so the two-item limit matters more. Treat the carry-on as shared space for the group, then keep each person’s under-seat item compact.
Strollers And Car Seats
Many families gate-check a stroller. Bring it to the gate, fold it when asked, and attach the tag. For a car seat, the smooth setup is a ticketed seat for the child and an FAA-approved car seat that fits the aircraft seat, so it stays out of the bins.
Pet Carrier Game Plan
A pet carrier usually takes one of your two slots and must stow under the seat. Plan around that from the start: either bring a slim personal item that still fits under the seat with the carrier, or use the carrier as the under-seat item and keep your second item up top.
One-Minute Fit Test Before You Leave For The Airport
Run this the night before your flight. It catches most carry-on problems while you still have time to swap bags.
- Measure your carry-on’s full outer size, including wheels and handles.
- Pack it fully, then recheck depth at the bulkiest point.
- Confirm your personal item can slide under a chair at home without forcing it.
- Move liquids into one quart-size bag and cap each container at 3.4 oz (100 ml).
- Put meds, ID, wallet, and chargers in the under-seat bag.
| Fast Scenario | What To Do | Payoff |
|---|---|---|
| Bag is 25 inches tall with wheels | Switch to a smaller carry-on or check it from the start | Avoid a gate check after you’ve packed |
| Personal item is a rigid briefcase | Swap to a soft backpack that compresses | Fits more seat rows with less fuss |
| You bought snacks like hummus or yogurt | Pack them in checked baggage or keep portions under 3.4 oz | Fewer screening delays |
| You’re boarding late | Put must-have items in the under-seat bag | You’re covered if bins fill |
| You’re carrying a jacket and a shopping bag | Stuff both inside your carry-on before boarding | Stay at two items |
| You’re flying with a pet in cabin | Plan the pet carrier as one of your two items | No last-second repacking |
| You want a final double-check | Compare your bag to Southwest’s posted dimensions | Match the rule staff use |
Carry-on Setup That Works For Most Southwest Trips
If you’re still thinking, “can you bring a carry-on on southwest?” because you’re packing for a short trip, this split keeps things tidy and reachable.
In The Carry-on (Overhead)
- Clothes and shoes in packing cubes or a compression bag
- Non-liquid snacks and an empty water bottle
- Bulky toiletries moved to checked baggage if they exceed 3.4 oz
In The Personal Item (Under Seat)
- Meds, glasses, and anything you can’t replace that day
- Chargers, power bank, headphones, and one small comfort item
- Liquids bag, so you can pull it out fast at screening
Final Preflight Card
If you’re asking, “can you bring a carry-on on southwest?” before you head out, do three checks: your carry-on is 24 x 16 x 10 inches or less with wheels, your under-seat bag compresses, and your liquids follow TSA’s rule.