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. Below: the official rules (cited), the honest under-seat caveat, and which carriers fit that limit.
📏 Short height: Height limit is only 8.5" — the same short ceiling as JetBlue. Standard 11"-tall carriers will not fit; choose a shorter or collapsible carrier.
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 |
| 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 2026-07-03
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 →
| Carrier | Size | Fit | Buy |
|---|---|---|---|
| Sherpa Original Deluxe (Small) | 15 × 10 × 8.5 in | Fits | See on Amazon → |
| Mr. Peanut's Gold Series Mini (Low-Profile) | 16 × 10.5 × 9.8 in | Flexes — check height | See on Amazon → |
| Sherpa Original Deluxe (Medium) | 17 × 11 × 10.5 in | Flexes — check height | See on Amazon → |
| Mr. Peanut's Gold Series Standard (Expandable) | 18.5 × 11.75 × 11.5 in | Flexes — check height | See on Amazon → |
| SturdiBag Pro (Large, Flexible Height) | 18 × 11.5 × 11.5 in | Flexes — check height | See on Amazon → |
| Diggs Passenger | 17 × 12 × 10.5 in | Too tall (10.5" > 8.5") | See on Amazon → |
| Petsfit Expandable Soft-Sided | 17 × 11 × 11 in | Too tall (11" > 8.5") | See on Amazon → |
| ibiyaya JetPaw Expandable Backpack | 18 × 12 × 12 in | Too tall (12" > 8.5") | See on Amazon → |
| Sleepypod Air | 22 × 10.5 × 10.5 in | Too big | See on Amazon → |
| Away The Pet Carrier | 18.7 × 10.8 × 10.75 in | Too big | See on Amazon → |
| Sherpa Original Deluxe (Large) | 19 × 11.75 × 11.5 in | Too big | See on Amazon → |
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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.
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