Petsfit Expandable Soft-Sided vs Sherpa Original Deluxe (Medium): which airline pet carrier?
Two of the most cross-shopped in-cabin carriers, compared the way an airline sees them: by published size against each under-seat limit. Petsfit Expandable Soft-Sided is 17 × 11 × 11 in; Sherpa Original Deluxe (Medium) is 17 × 11 × 10.5 in.
Side by side
| Property | Petsfit Expandable Soft-Sided | Sherpa Original Deluxe (Medium) |
|---|---|---|
| External size (L×W×H) | 17 × 11 × 11 in | 17 × 11 × 10.5 in |
| Type | soft-sided · expandable | soft-sided · flexible height |
| Pet weight | up to ~15 lb | up to ~16 lb |
| Airlines it fits outright | 5 of 12 | 5 of 12 |
Airline by airline
Green = within the published size; amber = fits only collapsed / flexed; grey = over. Height is strict — it's the dimension a seat won't negotiate on.
| Airline | Expandable Soft-Sided | Original Deluxe (Medium) |
|---|---|---|
| Delta Air Lines | Fits | Fits |
| JetBlue | Too tall (11" > 8.5") | Flexes — check height |
| American Airlines | Fits | Fits |
| United Airlines | Fits | Fits |
| Southwest Airlines | Too tall (11" > 8.5") | Flexes — check height |
| Alaska Airlines | Too tall (11" > 9.5") | Flexes — check height |
| Frontier Airlines | Fits | Fits |
| Air Canada | Too tall (11" > 8") | Flexes — check height |
| Allegiant Air | Fits | Fits |
| Sun Country Airlines | Too tall (11" > 9") | Flexes — check height |
| Hawaiian Airlines | Too tall (11" > 9.5") | Flexes — check height |
| Breeze Airways | Too big | Too big |
⚠️ "Fits" means within the published maximum — real under-seat space varies by aircraft and seat. See why →
Choose the Petsfit Expandable Soft-Sided if…
- Zips to a compliant 17×11×11 for boarding, expands for extra room at the gate. Budget-friendly.
- It clears 5 of 12 tracked airlines outright.
- Your pet is under ~15 lb.
Choose the Sherpa Original Deluxe (Medium) if…
- Spring-wire top flexes down to squeeze under lower seats. Guaranteed On Board®.
- It clears 5 of 12 tracked airlines outright.
- Your pet is under ~16 lb.
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Full profiles: Petsfit Expandable Soft-Sided · Sherpa Original Deluxe (Medium) · best carriers ranked · all carriers