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 →
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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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