Southwest Airlines Carry On Bag Policy 2026 | Size Limits & Personal Item Rules

Flying Southwest? Southwest runs one of the more relaxed carry-on policies among major U.S. airlines — unlike a strict clear-bag venue policy, the emphasis here is on size and self-sufficiency (can you lift it yourself?) rather than weight or material. Here’s exactly what’s allowed under the current Southwest Airlines carry-on policy.

Quick Answer: Southwest Airlines Carry On Bag Policy at a Glance

Southwest airlines carry on bag policy allows one free bag up to 24″ x 16″ x 10″ (including wheels and handles) and one free personal item that fits under the seat in front of you. There’s no weight restriction on either, though you must be able to lift your own carry-on into the overhead bin. This carry-on allowance hasn’t changed even as Southwest’s checked bag policy shifted significantly in 2025.

Official Policy Verification & Source Check

• Official policy source: Southwest Airlines’ official Carry-on Baggage Policy page (support.southwest.com/helpcenter/article/carryon-baggage-policy)
• Source type: Official airline support page
• Last checked: September 2026
• Confidence level: High
• Notes on conflicting figures: Every source checked agrees on the core carry-on and personal item rules — 24″x16″x10″ for the carry-on, “fits under the seat” for the personal item, no stated weight limit for either. The real point of confusion for travelers is the checked bag policy specifically: several third-party guides and forum comments still describe Southwest’s old “two free checked bags for everyone” perk as current, when that changed for most passengers starting May 2025. If you’re researching checked bags rather than carry-on rules, confirm which fare and Rapid Rewards tier you’re on, since the free-bag rules now vary significantly by status rather than applying universally the way they used to.

How We Check This Policy: We prioritize Southwest’s own official support page over travel blogs and third-party sites, and we specifically flag outdated information — like lingering references to the old universal free-checked-bag perk — since that’s the part of Southwest’s policy most likely to be stale in older content.

What Makes Southwest’s Carry-On Policy Different

Compared with Icelandair, which caps international carry-ons at a strict 10 kg (22 lbs) and weighs bags at the gate, Southwest states no weight limit at all for either the carry-on or personal item — the practical constraint is simply whether you can lift your own bag into the overhead bin. Southwest also doesn’t assign seats, and gate agents generally don’t weigh hand luggage, so enforcement in practice tends to be looser than the written size limit might suggest, according to frequent flyers.

One detail that’s easy to miss: Southwest specifically calls out infant items — FAA-approved car seats, diaper bags, breast pumps, and formula — as not counting toward your carry-on or personal item limit at all when traveling with a child, a more generous carve-out than many airlines offer.

Allowed Bags and Size Limits Under Southwest’s Carry-On Policy

Carry-On Bags

A duffel bag, roller bag, or large backpack up to 24″x16″x10″ (including wheels and handles) is the standard free allowance. There’s no stated weight limit, but you need to be able to lift it into the overhead bin yourself — on a full flight, an obviously oversized bag can still be asked to be checked or weighed.

Personal Items

Your personal item — a purse, laptop bag, small backpack, briefcase, or camera bag — needs to fit fully under the seat in front of you. Southwest doesn’t give an exact inch measurement for this one the way it does for the carry-on; “fits under the seat” is the functional test.

Infant and Mobility Items

These are genuine exceptions, not counted against your two-item allowance at all — useful if you’re already using your carry-on and personal item slots and traveling with a child or mobility equipment.

Checked Baggage: What Changed in 2025

Since May 2025, most passengers now pay for checked bags — $35 for the first, $45 for the second — a major shift from Southwest’s decades-long “Bags Fly Free” reputation. Free checked bags are still available, but now tiered by status:

• Rapid Rewards Credit Cardmembers: one free checked bag (for themselves and up to 8 others on the booking); second bag $45
• Rapid Rewards A-List Members: one free checked bag (same group rule); second bag $35
• Rapid Rewards A-List Preferred Members: two free checked bags
• Choice Extra Fare customers and active-duty military (valid ID): two free checked bags
• Southwest Groups customers: no free bags — standard fees apply
• Hawaii residents (interisland flights): two free checked bags, third bag $50

Checked bag size and weight limits are unchanged: 62″ total (length + width + height, including wheels/handles) and 50 lbs per bag. A third checked bag costs $150, oversized bag fees start at $200, and overweight fees start at $100 — combined oversized-and-overweight starts at a $200 minimum. Bags maxing out at 80″ total or 100 lbs can’t fly at all.

Prohibited and Restricted Items

• Liquids, gels, and aerosols over 3.4 oz per container (standard TSA rule) outside the carry-on liquids bag
• Self-defense sprays, banned specifically by Southwest in both carry-on and checked baggage
• Sharp objects and other standard TSA-restricted items
• Anything exceeding checked bag maximums (80″ total or 100 lbs)

Packing Strategy for Faster Boarding

• Measure your carry-on before you leave for the airport: 24″x16″x10″ including wheels and handles — a bag that looks “close enough” at home can still get flagged on a full flight.
• Pick a bag you can lift yourself: since there’s no stated weight limit, self-sufficiency is the real constraint gate agents care about.
• Use your personal item for anything you want under the seat, not the overhead bin: laptops, chargers, and anything you’ll need mid-flight.
• Keep infant and mobility items separate from your two standard bags: they don’t count against your allowance, so don’t squeeze formula or a diaper bag into your personal item unnecessarily.
• Check your Rapid Rewards tier before assuming checked bags are free: the old universal “Bags Fly Free” perk no longer applies to most standard-fare passengers.

Category-Specific Packing Tips

Families with infants: Take advantage of the free car seat, diaper bag, breast pump, and formula allowance — none of it counts against your carry-on or personal item, so pack your actual personal item for adult essentials instead.

Frequent flyers with Rapid Rewards status: Confirm your specific tier before booking if checked bags matter to your trip — A-List Preferred, Choice Extra, and active-duty military still get two free bags, while standard Rapid Rewards members get a smaller, tiered allowance.

Golf and ski trip travelers: Sports equipment can still be checked — a golf bag counts as one checked bag, and ski/snowboard gear (skis, poles, boots) can span two bags but counts as one item, subject to standard size/weight limits.

Business travelers using the “purse-in-backpack” trick: Some frequent flyers report nesting a smaller item inside a backpack to effectively bring three things aboard as two — Southwest doesn’t officially endorse this, so treat it as informal practice rather than guaranteed to work every time.

Before You Go Checklist

• [ ] Carry-on measured at or under 24″x16″x10″, including wheels and handles
• [ ] Personal item confirmed to fit under the seat ahead
• [ ] Confirmed whether your Rapid Rewards tier or fare includes free checked bags
• [ ] Checked bag(s), if any, under 50 lbs and 62″ total dimensions
• [ ] Liquids packed per standard TSA 3-1-1 rules
• [ ] Infant or mobility items packed separately from your two standard bag allowances

Southwest Carry-On Policy FAQs

Do bags still fly free on Southwest in 2026?
Carry-on bags and personal items are always free for every passenger. Checked bags are no longer free for most passengers as of May 2025 — free checked bags now depend on your Rapid Rewards tier, fare type, or military status.

Can I bring a backpack and a carry-on?
Yes — a backpack can serve as either your carry-on (if within 24″x16″x10″) or your personal item (if it fits under the seat), and you’re allowed one of each.

What happens if my carry-on is too big?
It will need to be checked, which may mean waiting in line or paying a fee if you don’t otherwise qualify for a free checked bag.

What about infant items?
Car seats, diaper bags, breast pumps, and formula are allowed free and don’t count toward your carry-on or personal item limit.

Are there any prohibited items?
Standard TSA rules apply, including the 3-1-1 liquids rule. Southwest also specifically prohibits self-defense sprays in both carry-on and checked baggage.

What if I have a medical device?
Medications, insulin kits, EpiPens, and mobility devices are permitted; liquid medications over 3.4 oz typically require accompanying documentation to pass security.

Related Bag Policies

• Icelandair Bag Policy Guide
• Carnival Cruise Bag Policy Guide

Conclusion

Southwest’s carry-on policy remains one of the more traveler-friendly in the industry: a free 24″x16″x10″ carry-on and a free personal item, no weight limit on either, for every passenger regardless of fare. The real shift to watch is on the checked-bag side — free checked bags are no longer universal, so check your Rapid Rewards tier or fare type before assuming the old “Bags Fly Free” perk still applies to your trip.