Which pet carriers fit each airline
Of the 15 in-cabin carriers we track, the number that clear each airline's published under-seat limit ranges from 0 (Air Transat) to 9 (Frontier Airlines). Height is the binding constraint almost every time — the limit airlines publish is a height test more than a footprint test.
| Airline | Under-seat limit | Carriers that clear it | Biggest that still fits |
|---|---|---|---|
| Delta Air Lines | 18 × 11 × 11 in | 8 of 15 +1 collapsed | Frisco Premium Airline-Compliant Carrier · 18 × 11 × 11 in |
| JetBlue | 17 × 12.5 × 8.5 in | 1 of 15 +2 collapsed | Sherpa Original Deluxe (Small) · 15 × 10 × 8.5 in |
| American Airlines | 18 × 11 × 11 in | 8 of 15 +1 collapsed | Frisco Premium Airline-Compliant Carrier · 18 × 11 × 11 in |
| United Airlines | 18 × 11 × 11 in | 8 of 15 +1 collapsed | Frisco Premium Airline-Compliant Carrier · 18 × 11 × 11 in |
| Southwest Airlines | 18.5 × 13.5 × 8.5 in | 1 of 15 +4 collapsed | Sherpa Original Deluxe (Small) · 15 × 10 × 8.5 in |
| Alaska Airlines | 17 × 11 × 9.5 in | 1 of 15 +2 collapsed | Sherpa Original Deluxe (Small) · 15 × 10 × 8.5 in |
| Frontier Airlines | 18 × 14 × 11 in | 9 of 15 +2 collapsed | Frisco Premium Airline-Compliant Carrier · 18 × 11 × 11 in |
| Air Canada | 17 × 16 × 8 in | 0 of 15 +3 collapsed | — |
| Allegiant Air | 18 × 12 × 11 in | 9 of 15 +2 collapsed | Frisco Premium Airline-Compliant Carrier · 18 × 11 × 11 in |
| Sun Country Airlines | 17 × 12 × 9 in | 1 of 15 +2 collapsed | Sherpa Original Deluxe (Small) · 15 × 10 × 8.5 in |
| Hawaiian Airlines | 17 × 11 × 9.5 in | 1 of 15 +2 collapsed | Sherpa Original Deluxe (Small) · 15 × 10 × 8.5 in |
| Breeze Airways | 17 × 8 × 13 in | 1 of 15 | Bergan Comfort Carrier (Small) · 16 × 8 × 11 in |
| WestJet | 16 × 10 × 8.5 in | 1 of 15 | Sherpa Original Deluxe (Small) · 15 × 10 × 8.5 in |
| Porter Airlines | 21.5 × 15.5 × 10.5 in | 6 of 15 +4 collapsed | Diggs Passenger · 17 × 12 × 10.5 in |
| Avelo Airlines | 17 × 9 × 13 in | 2 of 15 | Sleepypod Atom · 17 × 8.5 × 10.5 in |
| Air Transat | 17 × 9.5 × 10 in | 0 of 15 | — |
| JSX | 17 × 13 × 11 in | 8 of 15 +1 collapsed | Diggs Passenger · 17 × 12 × 10.5 in |
Start from the carrier instead: all carriers by size · best carriers ranked by how many airlines they fit →
Policies, fees and species rules per airline: all airline pet policies · not sure how to measure? the two measurements that matter · why the published size is optimistic