Petsfit (Medium) 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 (Medium) Expandable Soft-Sided is 17 × 11 × 11 in; Sherpa Original Deluxe (Medium) is 17 × 11 × 10.5 in.
Side by side
| Property | Petsfit (Medium) 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 ~13 lb | up to ~16 lb |
| Airlines it fits outright | 6 of 43 | 7 of 43 |
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 | (Medium) Expandable Soft-Sided | Original Deluxe (Medium) |
|---|---|---|
| Aegean Airlines | Too big | Too big |
| Air Canada | Too tall (11" > 8") | Flexes — 2.5" over |
| Air France | Too tall (11" > 9.4") | Flexes — 1.1" over |
| Air New Zealand | No cabin pets | No cabin pets |
| Air Transat | Too big | Too big |
| Alaska Airlines | Too tall (11" > 9.5") | Flexes — 1" over |
| Alaska Horizon (Horizon Air) | Too tall (11" > 9.5") | Flexes — 1" over |
| Allegiant Air | Exact fit | Fits |
| American Airlines | Exact fit | Exact fit |
| American Eagle (regional, incl. Republic Airways) | Too big | Too big |
| ANA (All Nippon Airways) | No cabin pets | No cabin pets |
| Austrian Airlines | Too tall (11" > 9.1") | Flexes — 1.4" over |
| Avelo Airlines | Too big | Too big |
| Avianca | Too tall (11" > 10") | Flexes — 0.5" over |
| Azul Linhas Aéreas | Size not published | Size not published |
| Breeze Airways | Too big | Too big |
| British Airways | No cabin pets | No cabin pets |
| Brussels Airlines | Too tall (11" > 9.1") | Flexes — 1.4" over |
| Cape Air | Too tall (11" > 8.5") | Flexes — 2" over |
| Cathay Pacific | No cabin pets | No cabin pets |
| China Airlines | No cabin pets | No cabin pets |
| Contour Airlines | Too tall (11" > 10") | Flexes — 0.5" over |
| Delta Air Lines | Exact fit | Exact fit |
| easyJet | No cabin pets | No cabin pets |
| EL AL Israel Airlines | Too big | Too big |
| Emirates | No cabin pets | No cabin pets |
| Etihad Airways | Too big | Too big |
| Finnair | Too big | Too big |
| Frontier Airlines | Exact fit | Fits |
| GOL Linhas Aéreas | Too big | Too big |
| Hawaiian Airlines | Too tall (11" > 9.5") | Flexes — 1" over |
| Iberia | Too tall (11" > 9.8") | Flexes — 0.7" over |
| ITA Airways | Too tall (11" > 9.1") | Flexes — 1.4" over |
| Japan Airlines | No cabin pets | No cabin pets |
| JetBlue | Too tall (11" > 8.5") | Flexes — 2" over |
| JSX | Exact fit | Exact fit |
| KLM Royal Dutch Airlines | Too tall (11" > 9.4") | Flexes — 1.1" over |
| Korean Air | Too tall (11" > 7.5") | Flexes — 3" over |
| Lufthansa | Too tall (11" > 9.1") | Flexes — 1.4" over |
| Norwegian | Too big | Too big |
| Porter Airlines | Too tall (11" > 10.5") | Exact fit |
| Qantas | No cabin pets | No cabin pets |
| Qatar Airways | No cabin pets | No cabin pets |
| Royal Air Maroc | Too tall (11" > 7.9") | Flexes — 2.6" over |
| Ryanair | No cabin pets | No cabin pets |
| SAS Scandinavian Airlines | Too big | Too big |
| Singapore Airlines | No cabin pets | No cabin pets |
| Southern Airways Express | Size not published | Size not published |
| Southwest Airlines | Too tall (11" > 8.5") | Flexes — 2" over |
| Sun Country Airlines | Too tall (11" > 9") | Flexes — 1.5" over |
| Swiss International Air Lines | Too tall (11" > 9.1") | Flexes — 1.4" over |
| TAP Air Portugal | Too tall (11" > 9") | Flexes — 1.5" over |
| Turkish Airlines | Too big | Too big |
| United Airlines | Exact fit | Exact fit |
| Virgin Atlantic | No cabin pets | No cabin pets |
| Volaris | Too tall (11" > 7.5") | Flexes — 3" over |
| Vueling | Too tall (11" > 8.3") | Flexes — 2.2" over |
| WestJet | Too big | Too big |
Which should you buy?
The Sherpa Original Deluxe (Medium) — it is within the published limit of 7 of the 43 airlines with a published cabin limit, against 6 for the Petsfit (Medium) Expandable Soft-Sided. That is the whole verdict on airline fit; real under-seat space still varies by aircraft and seat.
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Choose the Sherpa Original Deluxe (Medium) if…
- Spring-wire top flexes down to squeeze under lower seats. Guaranteed On Board®.
- It clears 7 of 43 airlines with a published cabin limit outright — more than the Petsfit (Medium) Expandable Soft-Sided.
- Your pet is under ~16 lb.
Choose the Petsfit (Medium) Expandable Soft-Sided if…
- Zips to a compliant 17×11×11 for boarding, expands for extra room at the gate. Budget-friendly.
- It clears 6 of 43 airlines with a published cabin limit outright.
- Your pet is under ~13 lb.
Full profiles: Petsfit (Medium) Expandable Soft-Sided · Sherpa Original Deluxe (Medium) · best carriers ranked · all carriers
Common questions
Which fits more airlines, the Petsfit (Medium) Expandable Soft-Sided or the Sherpa Original Deluxe (Medium)?
The Sherpa Original Deluxe (Medium) — it's within the published limit of 7 of the 43 airlines with a published cabin limit, against 6 for the other. Real under-seat space still varies by aircraft.
What's the size difference?
Petsfit (Medium) Expandable Soft-Sided: 17 × 11 × 11 in (up to ~13 lb). Sherpa Original Deluxe (Medium): 17 × 11 × 10.5 in (up to ~16 lb). Height is the strict dimension under a seat, and the Sherpa Original Deluxe (Medium) is the shorter of the two.
Are these figures measured or published?
Published — both sets of dimensions come from the manufacturers' product pages (linked on each carrier's profile), matched against each airline's official carrier limit. We don't invent measurements.