As one of the largest domestic carriers in the US, Southwest lets you bring one carry-on bag and one personal item at no extra cost. Here’s everything you need to know about Southwest’s carry-on size limits before your next flight.
Quick summary.
- Carry-on bags are completely free on Southwest, with every passenger entitled to one overhead bin bag and one personal item.
- Size limit is 24 x 16 x 10 inches for your carry-on, with no published weight limit — just lift it yourself.
- Lithium batteries must travel in your carry-on, never checked baggage, per FAA regulations.
- Strollers and car seats can be checked for free, but gate-checking requires a tag from the agent before boarding.
Southwest carry-on size: What you need to know.
All Southwest passengers are allowed one bag that goes in the overhead bin and a smaller item that fits under the seat in front of them. The larger bag size limit is 24 x 16 x 10 total inches, including wheels, handles and attachments. Southwest does not specify a weight limit.
Last updated and fact-checked: May 11, 2026.
Southwest carry-on bag size for personal items.
Your personal item must fit under the seat in front of you. Southwest does not publish specific size dimensions for personal items, but common examples include a purse, briefcase, laptop bag or small backpack. As long as it slides under the seat without blocking legroom, you’re good to go.
Is there a weight limit for Southwest carry-on bags?
Southwest does not publish a carry-on weight limit. However, you must be able to lift your bag into the overhead bin without assistance from the crew.
Southwest carry-on size policies for children’s items.
Like most US carriers, Southwest has fairly generous carry-on policies for parents or caregivers traveling with little ones. Strollers and car seats can be checked for free at the check-in counter or at the gate.
In addition, baggage containing a breast pump and/or breast milk may be brought onboard. These items do not count toward the standard carry-on limit. However, Southwest reminds passengers that they might be asked about the nature of the additional carry-on bag(s) during their trip.
Southwest policies for children with their own seat.
If your child has their own seat, they have the same carry-on allowances as adult passengers. However, if you are using a child restraint system (CRS), their seat counts toward one of those items. Note that car seats are allowed on board, but only in window seats.
Are strollers allowed as carry-on bags on Southwest?
That depends on a couple of factors. First, they must collapse small enough to fit within the maximum dimensions specified above. If it’s a full flight, you may be required to gate-check your stroller, so it’s highly recommended to be prepared for that possibility.
If you are planning to gate check your stroller on Southwest, be sure to get a tag from the gate agent prior to boarding. Amid the craziness of flying with young children, this can be an easy step to forget. But it’s an important one so you can board on time.
What extra items can you bring on board Southwest flights?
Southwest allows passengers to bring extra items on board that do not count toward the carry-on allowance. The following items are neither considered a carry-on bag or smaller personal item:
- assistive/mobility devices such as walking canes
- food in disposable packaging
- child restraint systems (or CRSs, as Southwest refers to them)
- wearable articles of clothing such as coats or wraps
- umbrellas
Carry-on rules for musical instruments on Southwest.
You may bring a musical instrument onboard if the instrument (along with its case) fits within the size requirements for carry-on items. If the instrument exceeds those dimensions, it might still be allowed onboard, but only if space is available and it will fit in an overhead bin.
Keep in mind that your only other allowed carry-on bag will be a personal item that fits under the seat in front of you.
If your instrument is too big to fit in an overhead bin or under a seat, you may purchase a seat for it. However, the following conditions must be met:
- It must not block aircraft signage
- It must be placed in the first row in a seat closer to the window than any passenger in the row
- It must fit in the seat and be secured with a seatbelt.
TSA liquid rules for Southwest carry-on bags.
Southwest follows standard TSA liquid rules for carry-on bags. Liquids, gels and aerosols must be in containers of 3.4 oz (100 ml) or less, and all containers must fit in a single quart-sized clear bag. Each passenger is allowed one bag.
This includes items like shampoo, toothpaste, lotion, contact lens solution and makeup. Medications, baby formula and breast milk are exempt, but may require additional screening.
Tip: Keep your liquids bag at the top of your carry-on for easy access at security – it helps speed things up.
Southwest carry-on FAQs.
Still have questions about Southwest carry-on bag size or other concerns? Find all the answers you need below.
Southwest does not charge for carry-on bags. Every passenger can bring one carry-on bag and one personal item at no extra cost, regardless of fare type.
Southwest allows each passenger to bring two items in the cabin: one carry-on bag that fits in the overhead bin and one personal item that goes under the seat in front of you. Both are included free with your ticket.
Southwest permits standard travel items in your carry-on, including clothing, toiletries (following TSA liquid rules), electronics and personal essentials. Lithium batteries and electronic cigarettes or vaping devices must be packed in your carry-on rather than checked baggage.
Southwest does not specify a weight limit, but you must be able to lift your carry-on bags without assistance.
Yes – in fact, they are only allowed in carry-on luggage, per Federal Aviation Administration regulations. Spare lithium batteries used for portable electronic devices and electronic cigarettes or vaping devices must be removed from checked or gate-checked baggage and carried onboard the aircraft. Because of the potential to generate heat and cause a fire, such items are strictly forbidden in checked baggage and must be transported in carry-on baggage only.
Top three Southwest carry-on luggage tips.
1. Bags aren’t free for everyone anymore.
Southwest’s baggage policy now varies by fare type and traveler status, with some passengers still eligible for free checked bags. This is great incentive to forgo the overhead bin battle altogether and just bring a personal item for your flight.
2. Southwest is changing how you pick your seat.
Southwest is moving away from its open seating model, with more structured seating rolling out through 2025 and beyond. If you’re used to choosing your seat on boarding, expect a different experience.
One thing that hasn’t changed: if you’re in the front row or an exit row, all carry-on items – including personal items – need to go in the overhead bin.
3. What happens when you gate-check a stroller.
If you decide to gate check a stroller or car seat, keep in mind that these items fall under what’s known as a limited release of liability. This is part of the fine print of Southwest’s contract of carriage, and it essentially means that the airline is not responsible if those items are damaged.
More ways to get luggage right.
Luggage policies can be confusing. For an easy way to compare carry-on rules across airlines, check out our carry-on luggage guide. Need help deciding between a carry-on or checked bag? Or perhaps you’re stuck on what to pack? We have plenty of handy tips for that, too. Finally, don’t forget to check what’s allowed in a carry-on before you head to the airport.
