Alpha One-Niner SERT, PENUMBRA 2.0 Backpack vs. Pakt Travel Backpack

Two carry-on travel backpacks, compared spec for spec.

Alpha One-Niner SERT, PENUMBRA 2.0 Backpack

Front facing view of the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack
Capacity21 L
Weight1.5 kg
Dimensions47×30×14 cm
Airline fit93%
Price$255

Feature by feature

Alpha One-Niner SERT, PENUMBRA 2.0 BackpackFeaturePakt Travel Backpack
Storage
2 Compression 2
None Expanded Capacity None
1 Opening 1
front Passport front
Y Passthrough Y
Carry
Y Backpack hideable
optional Hip Belt removable
removable Sternum Strap removable
Inside
16in Laptop 16in
5 Main Compartments 5
Y Organizer Y
Outside
× Hard Shell ×
N Rain-fly N
2, side Water Bottle Holder 1, side
Y Water Resistant Y
Material
Available in: X-Pac X42, 500D, 630D HD500D recycled nylon

Pakt Travel Backpack

by Pakt
Front facing view of the Pakt Travel Backpack
Capacity35 L
Weight1.9 kg
Dimensions55×32×21 cm
Airline fit69%
Price$325

Key differences between the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack and Pakt Travel Backpack

Both have: compression straps, passport pocket, luggage passthrough, sternum strap, laptop sleeve, built-in organizer, water resistant.

Which airlines take each bag as a carry-on

We checked both bags against the carry-on size limits of 189 airlines. 130 accept both. 45 accept only the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack, and 0 accept only the Pakt Travel Backpack.

Only the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack fits

Air Baltic, Air China, Air Malta, Air Niugini, Air Serbia, Air Seychelles, Asiana Airlines, ATA Airlines, Belavia, Blue Air, Bulgaria Air, China Eastern, Emirates Airlines, Enter Air, Etihad Airways, flybe, Icelandair, InselAir, Juneyao Airlines, Liat Airlines, Luxair, Meridiana Fly, Nordwind Airlines, Oman Air, Qatar Airways, Regional Express, Royal Brunei Airlines, Royal Jordanian, Ryanair, S7, Scoot, Shandong Airlines, Shenzhen Airlines, Sun Express, TAP Air Portugal, TAROM, Tianjin Airlines (A320 & E190), Tiger Airways, TUI, Ukraine International, VIM Airlines (Closed), Virgin Australia, Volotea, WestJet, Xiamen.

Alpha One-Niner SERT, PENUMBRA 2.0 Backpack vs. Pakt Travel Backpack: which should you pack?

The Pakt Travel Backpack carries 14L more than the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack (21L vs. 35L), while the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack is the lighter pack at 1.5kg (vs. 1.9kg). For carry-on flexibility, the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack fits 93% of the airlines we track — the higher of the two. If you prioritise packing volume, choose the Pakt Travel Backpack; if you want to travel lighter, the Alpha One-Niner SERT, PENUMBRA 2.0 Backpack is the better call.