Diggs Passenger vs SturdiBag Pro (Large, Flexible Height): 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. Diggs Passenger is 17 × 12 × 10.5 in; SturdiBag Pro (Large, Flexible Height) is 18 × 11.5 × 11.5 in.
Side by side
| Property | Diggs Passenger | SturdiBag Pro (Large, Flexible Height) |
|---|---|---|
| External size (L×W×H) | 17 × 12 × 10.5 in | 18 × 11.5 × 11.5 in |
| Type | soft-sided | soft-sided · flexible height |
| Pet weight | — | — |
| Airlines it fits outright | 2 of 12 | 0 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 | Passenger | Pro (Large, Flexible Height) |
|---|---|---|
| Delta Air Lines | Too big | Too big |
| JetBlue | Too tall (10.5" > 8.5") | Too big |
| American Airlines | Too big | Too big |
| United Airlines | Too big | Too big |
| Southwest Airlines | Too tall (10.5" > 8.5") | Flexes — check height |
| Alaska Airlines | Too big | Too big |
| Frontier Airlines | Fits | Flexes — check height |
| Air Canada | Too tall (10.5" > 8") | Too big |
| Allegiant Air | Fits | Flexes — check height |
| Sun Country Airlines | Too tall (10.5" > 9") | Too big |
| Hawaiian Airlines | Too big | Too big |
| 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 Diggs Passenger if…
- Structured, well-ventilated design; sits within the 18×11×11 airlines but its 10.5" height rules out the 8.5" airlines.
- It clears 2 of 12 tracked airlines outright — more than the SturdiBag Pro (Large, Flexible Height).
Choose the SturdiBag Pro (Large, Flexible Height) if…
- The flexible-height top is the whole point — it compresses down to slide under lower seats, then springs back. A common pick for the 8.5" airlines (compresses; verify for your specific seat).
- It clears 0 of 12 tracked airlines outright.
Affiliate link — we may earn a small commission at no extra cost to you. It never changes our specs or which carriers we list.
Full profiles: Diggs Passenger · SturdiBag Pro (Large, Flexible Height) · best carriers ranked · all carriers