Southwest Airlines Carry-On Policy 2026: Free Carry-On, 24 x 16 x 10 Size Limit
Southwest keeps cabin baggage simple: one free carry-on and one free personal item for every passenger, on every fare. Your carry-on can measure up to 24″ × 16″ × 10″ including wheels and handles, and your personal item simply has to slide completely under the seat in front of you. There is no stated weight limit — but you must be able to lift the bag into the overhead bin yourself.
In an era of basic-economy traps and carry-on fees, Southwest’s policy is a throwback: two cabin items, included, no fare-class games. The only real risks are size — an oversized roller gets checked — and forgetting that a pet carrier uses up one of your two items. This guide covers the measurements, the exceptions, and the easy wins (hello, free neck pillow) before you fly.
The Two Items, Explained
Your carry-on: the overhead bag
One bag per passenger rides in the overhead bin: a roller, small suitcase, garment bag or duffel, up to 24 inches long × 16 inches wide × 10 inches high. That measurement is the bag as it will actually board — wheels, handles and exterior attachments all count. Measure honestly at home; a bag that’s over gets checked at the ticket counter or gate-checked during boarding.
Your personal item: the under-seat bag
Your second free item lives under the seat in front of you, and that’s the only test it has to pass — Southwest publishes no numerical dimensions for it. Purses and crossbody bags, briefcases, laptop cases, backpacks and small camera bags all qualify. Pack it reasonably flat so it slides fully under without swallowing your foot space.
At a Glance: Bags and Where They Go
| Item | Limit | Where It Travels |
|---|---|---|
| Carry-on (roller, duffel, garment bag) | 1 free, 24″ × 16″ × 10″ | Overhead bin |
| Personal item (purse, laptop case, backpack) | 1 free, must fit under seat | Under the seat in front of you |
| Neck pillow / blanket | Does not count | Carried or worn — a genuine free extra |
| Pet carrier (airline-approved) | Counts as carry-on or personal item | Per pet policy — never a third free item |
| Oversized roller | Over 24″ × 16″ × 10″ | Checked at counter or gate-checked |
Why Southwest Is Different
Both items are free for everyone. There is no restrictive basic fare that strips the carry-on, and no gate surcharge for using the bin. And there’s no weight cap to hit: the policy is about dimensions and one practical test — can you lift your own bag into the overhead bin unassisted? If you can’t, it isn’t a carry-on, whatever it measures.
Southwest boards by group and the bins fill in order. If you’re in a late group, pack a small packable tote inside your personal item holding your medication, chargers and valuables — if your roller gets gate-checked (free, but still), everything important stays with you.
Rules That Sit Alongside Southwest’s
Southwest’s size policy doesn’t replace TSA rules. The TSA’s prohibited list (firearms, sharp objects, tools over 7 inches) and the 3-1-1 liquids rule (containers of 3.4 oz or less in one quart bag) still apply at security. Lithium batteries, power banks and e-cigarettes must travel in the cabin, never in checked bags. And if any leg of your trip is on a partner airline, that carrier’s carry-on dimensions and personal-item rules apply to that leg — don’t assume Southwest’s numbers transfer.
✓ Pack This Way
- Carry-on measured with wheels and handles inside 24″ × 16″ × 10″
- Personal item packed flat enough to disappear under the seat
- Liquids bag and power bank easy to reach for screening
- Everything consolidated to two items before the gate
✗ Avoid These Mistakes
- Measuring your roller without its wheels and pull handle
- Counting a pet carrier as a bonus third item
- Assuming partner-airline flights use Southwest’s sizes
- Packing power banks or vapes in a bag you might check
Before You Leave for the Airport
- Carry-on measured: 24″ × 16″ × 10″ or smaller, fully packed
- Under-seat test done: personal item slides completely under a seat-sized space
- TSA basics checked: liquids, batteries and restricted items sorted
- Partner flights reviewed, if your itinerary mixes airlines
- Essentials staged in a packable tote in case of a gate check
Southwest Carry-On Policy FAQs
How many bags can I take on Southwest for free?
Two cabin items: one carry-on for the overhead bin and one personal item for under the seat — free on every fare type.
What is Southwest’s carry-on size limit?
24″ × 16″ × 10″, and that includes wheels, handles and anything attached to the outside of the bag.
How big can my personal item be?
Southwest gives no fixed numbers. The rule is functional: it must fit completely under the seat in front of you.
Is there a weight limit?
None is stated. You do have to be able to lift your carry-on into the overhead bin yourself.
Does a pet carrier count as one of my bags?
Yes — the carrier takes the place of either your carry-on or your personal item; it is not an extra free item.
What if my bag doesn’t fit or the bins are full?
An oversized bag is checked at the ticket counter; a compliant bag that can’t be stowed can be gate-checked during boarding.
Do neck pillows count against my allowance?
No — neck pillows and blankets are specifically excluded from the two-item count.
Two free cabin items, a workable 24″ × 16″ × 10″ carry-on allowance, no weight limit and no fare-class tricks — Southwest’s carry-on policy is about as friendly as US flying gets. Measure with the wheels on, keep your personal item flat, and you’ll board without a conversation at the gate. Flying internationally next? Our British Airways baggage policy guide shows a very different, fare-based system.
Last checked against Southwest Airlines’ official carry-on guidance: October 2026. Airline policies change — confirm on southwest.com before you fly.
Check the Latest Bag Policy Before You Go
Bag requirements can vary depending on the event, performer, league, venue, or current security measures. Always check the official venue’s latest bag policy before your visit to make sure your bag meets the current requirements.
