Southwest Airlines in-cabin pet policy — and the carriers that fit
Southwest Airlines allows small pets in the cabin in a carrier up to 18.5 × 13.5 × 8.5 in, stowed under the seat in front of you. Already own a carrier? Enter its measurements below to check it against this limit. The in-cabin fee is $125 each way. 1 of the 15 carriers we track clears that published limit.
The only one that clears it — the Sherpa Original Deluxe (Small) — matches Southwest's published limit exactly, with no measurable slack, so measure your own carrier before you fly. Southwest's 8.5" height ceiling sits mid-pack among the 58 airlines we track (shared with Cape, JetBlue, WestJet): Aegean, Air France, Air Transat and Alaska allow more, while EL AL Israel allows only 7".
Will your carrier fit Southwest Airlines?
Measure the outside of your carrier (bulges included) and enter it below. The check uses Southwest Airlines’s published 18.5 × 13.5 × 8.5 in limit — height is checked strictly, the footprint may rotate.
Southwest Airlines pet rules
| Recommended max carrier (soft) | 18.5 × 13.5 × 8.5 in |
| Soft-sided required? | Soft recommended; hard allowed within its limit |
| In-cabin fee | $125 each way · compare all airlines → |
| Species allowed | cats, dogs |
| Pets | 1 carrier per passenger; 2 same-species pets may share one compliant carrier |
| Booking | Add at the airport or by calling; limited pets per flight |
Source: official Southwest Airlines pet policy · verified 2026-07-23
Carriers that fit Southwest Airlines
Matched to Southwest Airlines's published 18.5 × 13.5 × 8.5 in limit (height checked strictly; footprint may rotate). See the full Southwest Airlines carrier shortlist →
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| Carrier | Size | Fit | Buy |
|---|---|---|---|
| 15 × 10 × 8.5 in | Fits 0" spare | See on Amazon → | |
| 16 × 10.5 × 9.8 in | Flexes — check height | See on Amazon → | |
| 17 × 11 × 10.5 in | Flexes — check height | See on Amazon → | |
| 18.5 × 11.75 × 11.5 in | Flexes — check height | See on Amazon → | |
| 18 × 11.5 × 11.5 in | Flexes — check height | See on Amazon → | |
| 17 × 10 × 10 in | Too tall (10" > 8.5") | See on Amazon → | |
| 17 × 12 × 10.5 in | Too tall (10.5" > 8.5") | See on Amazon → | |
| 17 × 8.5 × 10.5 in | Too tall (10.5" > 8.5") | See on Amazon → | |
| 17 × 11 × 11 in | Too tall (11" > 8.5") | See on Amazon → | |
| 16 × 8 × 11 in | Too tall (11" > 8.5") | See on Amazon → | |
| 18 × 11 × 11 in | Too tall (11" > 8.5") | See on Amazon → | |
| 18 × 12 × 12 in | Too tall (12" > 8.5") | See on Amazon → | |
| 22 × 10.5 × 10.5 in | Too big | See on Amazon → | |
| 18.7 × 10.8 × 10.75 in | Too big | See on Amazon → | |
| 19 × 11.75 × 11.5 in | Too big | See on Amazon → |
How to confirm your actual under-seat space
Southwest Airlines's number is a fleet-wide recommendation, not a promise for your exact seat. Before you buy or fly:
- Check which aircraft operates your flight (in your booking or on a seat-map site).
- Avoid bulkhead and some window seats — they have less (or no) under-seat storage.
- Call Southwest Airlines to confirm under-seat dimensions for that aircraft, or
- Choose a collapsible / flexible-height carrier that adapts to a tighter space.
More airlines: Air Canada · Alaska Airlines · Allegiant Air · American Airlines · Breeze Airways · Delta Air Lines · Frontier Airlines · United Airlines · WestJet · all →
Common questions
What size pet carrier does Southwest Airlines allow in the cabin?
Southwest Airlines's recommended maximum in-cabin carrier is 18.5 × 13.5 × 8.5 in. It must fit fully under the seat in front of you. Source: the Southwest Airlines pet policy.
How much does Southwest Airlines charge for an in-cabin pet?
$125 each way. Always confirm the current fee on the official Southwest Airlines pet page before you fly.
Which pet carriers fit Southwest Airlines?
1 of the 15 carriers we track clears Southwest Airlines's published 18.5 × 13.5 × 8.5 in. The roomiest is the Sherpa Original Deluxe (Small), and even that one matches the limit exactly rather than clearing it, so measure before you fly. Full shortlist: /fits/southwest/.
Does Southwest Airlines require a soft-sided pet carrier?
Southwest Airlines recommends soft-sided but allows a hard-sided kennel within its published limit. Height is what rules carriers out: Southwest Airlines publishes 8.5", against 13" at the most generous airline we track.
How many pets can I bring in the cabin on Southwest Airlines?
1 carrier per passenger; 2 same-species pets may share one compliant carrier. Species accepted: cats, dogs. Add at the airport or by calling; limited pets per flight