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Updated February 2026 · 10 min read
Southwest Airlines is one of the most traveler-friendly carriers when it comes to carry-on enforcement. With their 24″ × 16″ × 10″ limit and lenient gate agents, most 40L travel backpacks work perfectly. Unlike budget carriers, Southwest includes two free checked bags, so there’s zero pressure to squeeze oversized items into carry-ons. This guide covers which backpacks fit, what to expect at the gate, and why Southwest is easier than most airlines.
The Southwest Reality
Carry-On Limit: 24″ × 16″ × 10″ (most generous US carrier)
Personal Item: 18.5″ × 8.5″ × 13.5″
Enforcement: Lenient – rarely measure unless obviously oversized
Bonus: 2 free checked bags (no pressure to carry-on)
Southwest’s Carry-On Policy
Southwest operates the most generous carry-on policy among major US carriers:
The Southwest Advantage
Southwest’s 24″×16″×10″ carry-on limit is larger than United (22″×14″×9″), Delta (22″×14″×9″), and American (22″×14″×9″). Plus, you get TWO free checked bags, so there’s no financial pressure to carry everything on. Gate agents are relaxed because Southwest’s business model doesn’t depend on baggage fees.
Best Backpacks for Southwest Airlines
Southwest’s generous 24″×16″×10″ limit means virtually all travel backpacks fit comfortably:
Osprey Farpoint 40
$111 • 40L • 21.3″×13.8″×9.1″
Fits Southwest comfortably with room to spare. The 10″ depth limit means even fully packed Farpoint bags (9.1″) have clearance. Excellent hip belt, proven reliability, unbeatable price. The default choice for Southwest travelers.
Cotopaxi Allpa 35L
$220 • 35L • 20″×12″×10″
Fits Southwest’s limit exactly (10″ depth matches perfectly). Great organization, 35L sweet spot capacity, ethical brand (B-Corp). The 10″ depth that causes issues on other airlines works perfectly on Southwest.
Osprey Fairview 40
$200 • 40L • 21.3″×13.8″×9.1″
Women’s version of Farpoint. Same Southwest compatibility with plenty of clearance. Women-specific fit (shorter torso, contoured hip belt). Best for women 5′-5’8″.
Tortuga Travel Backpack Pro
$350 • 40L • 21″×13.5″×9″
Built like a tank for digital nomads. Fits Southwest with clearance on all dimensions. 1680D ballistic nylon lasts 10+ years. Heavy (4.4 lbs) but worth it for frequent Southwest travelers.
Frequently Asked Questions
Can I bring a 40L backpack on Southwest?
Yes, absolutely. Southwest’s 24″×16″×10″ carry-on limit is the most generous among US carriers. All popular 40L travel backpacks (Farpoint, Fairview, Allpa, Tortuga) fit comfortably with clearance. Gate agents rarely measure bags.
Does Southwest measure carry-on bags?
Rarely. Southwest gate agents prioritize boarding speed and don’t use sizing cages unless bags are obviously oversized (50L+ hiking packs). The generous 24″×16″×10″ limit plus two free checked bags means there’s no pressure on enforcement.
What happens if my bag doesn’t fit on Southwest?
You get a free checked bag. Southwest includes TWO free checked bags with every ticket, so gate-checking is completely free with no penalty. This is Southwest’s biggest advantage over other airlines.
Why is Southwest better for carry-ons than other airlines?
Three reasons: (1) Larger limit (24″×16″×10″ vs 22″×14″×9″), (2) Lenient enforcement (no sizing cage harassment), (3) Two free checked bags means zero pressure to carry-on. Southwest’s business model doesn’t depend on baggage fees, so gate agents are relaxed.
Last updated: February 2026
Note: Southwest Airlines policies change frequently. Always verify current limits on Southwest’s website before travel.
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