Tom Bihn Synapse 25 vs. Deuter Transit 40

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

Tom Bihn Synapse 25

Front facing view of the Tom Bihn Synapse 25
Capacity25 L
Weight0.8 kg
Dimensions51×34×23 cm
Airline fit71%
Price$250

Feature by feature

Tom Bihn Synapse 25FeatureDeuter Transit 40
Storage
N Compression Y
None Expanded Capacity None
0 Opening 0
front Passport front
N Passthrough N
Carry
Y Backpack hideable
removable Hip Belt hideable
removable Sternum Strap
Inside
15in Laptop 15in
6 Main Compartments 6
Y Organizer N
Outside
× Hard Shell ×
N Rain-fly N
1, front Water Bottle Holder
Y Water Resistant Y
Material
200 denier Halcyon/nylon ripstop fabric lining 400 denier nylon lower back600d Polytex

Deuter Transit 40

Front facing view of the Deuter Transit 40
Capacity40 L
Weight1.9 kg
Dimensions56×34×25 cm
Airline fit25%
Price$150

Key differences between the Tom Bihn Synapse 25 and Deuter Transit 40

Both have: passport pocket, laptop sleeve, water resistant.

Which airlines take each bag as a carry-on

We checked both bags against the carry-on size limits of 189 airlines. 48 accept both. 86 accept only the Tom Bihn Synapse 25, and 0 accept only the Deuter Transit 40.

Only the Tom Bihn Synapse 25 fits

Aer Lingus, Aeroflot, Aerolineas Argentinas, Aeromexico, Air Asia, Air Canada, Air Caraibes, Air France, Air India, Air Macau, Air Mauritius, Air Wisconsin, AirAsiaX, Alaska Airlines, All Nipon Airways, Allegiant Air, American Airlines, ANA, Austrian, Avianca , Azerbaijan Airlines, Bahamasair, Bangkok Airways, Biman Bangladesh, Boliviana de Aviacion, Brussels Airlines, Cambodia Angkor Air, Caribbean Airlines, Cathay Pacific, Cayman Airways, Cebu Pacific, China Airlines, CommutAir, Croatia Air, Czech Airlines, Delta Airlines, Dragonair, Ethiopian Airlines, Eurowings, EVA Air, Fiji Airways, Flair Air, Garuda Indonesia, Gol Linhas Aereas, Hawaiian Airlines, Hong Kong Airlines, Iberia, Indigo, Interjet, Iran Air, Japan Airlines, Jet Airways, jetBlue Airways, Jetstar Airways, Jetstar Asia, Kenya Airways, KLM, Kulula, LATAM , LOT Polish, Lufthansa, Mahan Air, Malaysia Airlines, Mango, Mesa Airlines, Norwegian, Oman Air, Peach, Porter Airlines, Qantas Airways, Republic Airways, Royal Jordanian, SAS Scandinavian, Scoot, Sky Airlines, Skywest, Inc., South African Airways, SriLankan Airlines, Swiss Int'l Air Lines, Tiger Airways, Trans States, Turkish Airlines, United Airlines, Vietnam Airlines, Virgin Atlantic, WestJet.

Tom Bihn Synapse 25 vs. Deuter Transit 40: which should you pack?

The Deuter Transit 40 carries 15L more than the Tom Bihn Synapse 25 (25L vs. 40L), while the Tom Bihn Synapse 25 is the lighter pack at 0.8kg (vs. 1.9kg). For carry-on flexibility, the Tom Bihn Synapse 25 fits 71% of the airlines we track — the higher of the two. If you prioritise packing volume, choose the Deuter Transit 40; if you want to travel lighter, the Tom Bihn Synapse 25 is the better call.