The Ultimate Guide to Southwest Airlines Carry-On Policies: Pack Smart, Fly Free (or Almost!)
Hey there, fellow traveler! Ever stood in front of your packed suitcase, wondering if it's too big for your Southwest flight? Or perhaps you've heard the horror stories of gate agents making people check bags they thought were carry-ons? You're not alone! Navigating airline baggage policies can feel like deciphering ancient hieroglyphs. But fear not, because today, we're going to demystify Southwest Airlines' carry-on rules, providing you with a step-by-step guide to ensure your next flight is as smooth and baggage-fee-free as possible. Let's dive in, shall we?
Step 1: Understand the Golden Rule of Southwest Carry-Ons – Your Two Freebies!
Alright, first things first. Southwest Airlines has long been lauded for its generous baggage policy, a stark contrast to many other airlines that nickel and dime you for every little thing. While recent changes have impacted checked baggage for some fare types (more on that later!), the carry-on policy remains quite traveler-friendly.
Here's the core principle: Every passenger on Southwest Airlines is allowed to bring:
One (1) Carry-On Bag: This is your primary bag, typically a small suitcase or rolling bag, designed to fit in the overhead bin.
One (1) Personal Item: This is a smaller bag, like a purse, laptop bag, or small backpack, intended to fit under the seat in front of you.
That's right, two items, absolutely free! This is a fantastic perk that can save you a significant amount of money and time at the airport. So, if you can master the art of packing light, you're already ahead of the game.
Step 2: Grasping the All-Important Dimensions – Measure Twice, Fly Once!
This is where the rubber meets the road, or rather, where your bag meets the sizer! Knowing the exact dimensions is crucial.
Sub-heading 2.1: Carry-On Bag Dimensions
For your main carry-on bag, Southwest Airlines stipulates that it should not exceed:
24 inches (L) x 16 inches (W) x 10 inches (H)
This translates to 50 linear inches (length + width + height).
Important Note: These dimensions include handles and wheels! Don't make the mistake of measuring just the bag's body. That extra inch or two from a bulky handle can be the difference between an overhead bin and a gate check.
Sub-heading 2.2: Personal Item Dimensions
Your personal item needs to be smaller and must fit under the seat in front of you. The recommended dimensions for a personal item are:
18.5 inches (L) x 13.5 inches (W) x 8.5 inches (H)
Think about items like:
Purses
Briefcases
Laptop bags
Small backpacks
Camera bags
Pro Tip: While Southwest doesn't typically have a specific weight limit for carry-on bags (unlike some other airlines), you must be able to lift your carry-on into the overhead bin without assistance. If you can't, it's likely too heavy.
Step 3: Packing Smart – Maximizing Your Carry-On Space
Now that you know the numbers, let's talk strategy. Packing efficiently is key to staying within the limits.
Sub-heading 3.1: The Art of Rolling vs. Folding
There's a long-standing debate among travelers: roll or fold? For carry-on packing, rolling your clothes tightly often proves to be the most space-efficient method. It can also help minimize wrinkles. Experiment with both to see what works best for your clothing items.
Sub-heading 3.2: Invest in Packing Cubes (Your New Best Friend!)
Seriously, if you don't use packing cubes, you're missing out! These zippered fabric containers help compress your clothes, keep them organized, and allow you to fit more into your bag. They come in various sizes, so you can designate specific cubes for different types of clothing (e.g., shirts, pants, underwear).
Sub-heading 3.3: Wear Your Bulkiest Items
If you're bringing a chunky sweater, a heavy jacket, or bulky shoes, wear them onto the plane rather than packing them. This immediately frees up valuable space in your carry-on. You can always take them off once you're settled.
Sub-heading 3.4: The "3-1-1" Rule for Liquids
Don't forget the TSA's (Transportation Security Administration) rules for liquids in carry-on bags. This is universally applied across all airlines flying within or from the US:
3.4 ounces (100 milliliters) per container.
All liquid containers must fit into one (1) quart-sized, clear, sealable plastic bag.
One (1) bag per passenger.
Remember to place this bag in an easily accessible spot in your carry-on, as you'll need to remove it for security screening.
Step 4: Special Items and Exceptions – What Else Can You Bring?
Beyond your standard carry-on and personal item, Southwest allows a few other things that don't count towards your limit:
Sub-heading 4.1: Assistive Devices
Wheelchairs, crutches, canes, walkers, and other mobility aids are welcome and do not count against your carry-on allowance.
There is no limit to the number of assistive devices a customer can bring on board.
Sub-heading 4.2: Child Restraint Systems & Strollers
Child restraint devices (car seats) for ticketed children with reserved seats, or when complimentary space is available, are permitted.
Strollers can generally be gate-checked for free or, if they collapse small enough to fit within carry-on dimensions, may be brought into the cabin if space allows. Always be prepared to gate-check a stroller, especially on full flights.
Sub-heading 4.3: Musical Instruments
If your instrument (including its case) is within the standard carry-on dimensions, you may bring it as your carry-on item if there's space.
Larger instruments might be allowed if they can fit in an overhead bin or under a seat and space is available.
For very large instruments, you might need to purchase an additional seat for them, or they may need to be checked. Refer to Southwest's official policy for specifics on oversized instruments.
Sub-heading 4.4: Outer Garments, Food, and Umbrellas
Outer garments (coats, wraps) and other wearable articles of clothing do not count.
Food for consumption during the flight in disposable packaging is generally allowed.
Walking canes or umbrellas are also permitted without counting towards your allowance.
Step 5: What Happens If Your Carry-On is Too Big? – The Gate Agent Gauntlet
This is the scenario every traveler wants to avoid. If your bag obviously exceeds the dimensions, or if overhead bin space is limited, here's what might happen:
Sub-heading 5.1: The Sizer Test
At the gate, Southwest agents (like most airlines) have bag sizers. These are metal frames designed to ensure bags meet the specified dimensions. If your bag looks questionable, you might be asked to place it in the sizer. If it doesn't fit, it's not going on as a carry-on.
Sub-heading 5.2: Gate Checking
If your carry-on is deemed too large or if there's no overhead space left, you will be required to gate-check your bag. This means it will be taken from you at the jet bridge and placed in the plane's cargo hold. You'll then pick it up at baggage claim at your destination (just like a regular checked bag).
Sub-heading 5.3: Potential Fees (Especially for Checked Bags)
While gate-checking a carry-on due to space limitations usually doesn't incur a fee, keep in mind that Southwest's generous "bags fly free" policy for checked bags has seen some recent changes, primarily affecting tickets booked or changed on or after May 28, 2025, for certain fare types.
For "Basic," "Wanna Get Away Plus®," and "Anytime" fares booked/changed on or after May 28, 2025: You will now be charged for checked bags ($35 for the first, $45 for the second).
A-List Preferred Members, Business Select® fares, A-List Members, and Rapid Rewards Credit Cardmembers may still receive free checked bags.
So, if your carry-on is too big and has to be checked, and your fare type is now subject to fees, you could end up paying for it! This makes getting your carry-on right even more important.
Step 6: The Importance of Early Boarding (Southwest's Unique System)
Southwest Airlines is famous for its open seating policy. This means there are no assigned seats, and boarding is based on a group and position number (A1-A60, B1-B60, C1-C60).
Why does this matter for your carry-on? The earlier you board, the more likely you are to find overhead bin space directly above your seat. Passengers boarding in the later "C" groups often find overhead bins full, potentially leading to their carry-on being gate-checked, even if it's within the size limits.
Sub-heading 6.1: How to Get an Early Boarding Position
Check-in exactly 24 hours before your flight: This is the most common way to secure a good boarding position. Set an alarm!
Purchase EarlyBird Check-In: This is an optional add-on that automatically checks you in 36 hours before your flight, typically securing a better boarding position.
Fly Business Select: These fares come with a guaranteed A1-A15 boarding position.
Be an A-List or A-List Preferred Member: These elite status members also receive preferential boarding.
Step 7: Final Checks Before You Head to the Airport – Don't Forget the Essentials!
Before you leave for the airport, do a quick mental checklist:
Is your carry-on truly within the dimensions, including wheels and handles? If you have any doubt, measure it again!
Is your personal item small enough to fit comfortably under the seat?
Are all your liquids in a quart-sized bag and easily accessible for security?
Do you have any prohibited items? (e.g., large scissors, flammable liquids, weapons – check TSA guidelines if unsure).
Can you comfortably lift your carry-on into an overhead bin?
By following these steps, you'll be well-prepared to breeze through security and onto your Southwest flight with your perfectly sized carry-on, ready for your adventure!
10 Related FAQ Questions
Here are some common questions about Southwest Airlines carry-on policies, with quick answers:
How to determine if my bag is too big for Southwest? Measure your bag's length, width, and height, including wheels and handles. If it exceeds 24 x 16 x 10 inches, it's too big for the overhead bin and will likely need to be checked.
How to pack efficiently to maximize carry-on space for Southwest? Use packing cubes, roll your clothes tightly, wear your bulkiest items, and only bring essential toiletries in travel-sized containers following the 3-1-1 rule.
How to know if I need to pay for a checked bag on Southwest if my carry-on is too big? If your fare type is "Basic," "Wanna Get Away Plus®," or "Anytime" (booked/changed on or after May 28, 2025), and your carry-on has to be checked, you will likely incur a checked bag fee. A-List/A-List Preferred, Rapid Rewards Credit Cardmembers, and Business Select fares may still get free checked bags.
How to bring a musical instrument on Southwest as a carry-on? If the instrument (including case) is within 24 x 16 x 10 inches, it can be your carry-on if space allows. Larger instruments may require purchasing an extra seat or checking as baggage.
How to travel with a pet on Southwest as a carry-on? Small, vaccinated domestic cats and dogs in an appropriate carrier are allowed in the cabin on domestic flights, provided the carrier fits under the seat in front of you. A pet fare applies, and reservations are recommended.
How to bring breast milk or a breast pump on Southwest? Bags containing a breast pump and/or breast milk are allowed onboard and do not count toward the standard carry-on limit.
How to avoid gate-checking my carry-on on Southwest? Ensure your bag strictly adheres to the dimensions, check in exactly 24 hours before your flight to get an early boarding position, or consider purchasing EarlyBird Check-In to secure better overhead bin space.
How to handle liquids in my Southwest carry-on? All liquids, gels, and aerosols must be in containers 3.4 ounces (100 milliliters) or less, fit in one quart-sized clear plastic bag, and be removed from your carry-on for security screening.
How to bring a stroller on Southwest? Strollers can be checked for free at the check-in counter or at the gate. If it collapses small enough to fit within carry-on dimensions, it might be allowed in the cabin if space is available, but gate-checking is more common.
How to check current TSA prohibited items for Southwest carry-ons? Always refer to the official TSA website for a comprehensive and up-to-date list of prohibited items to ensure your carry-on is compliant.
