STM Prime vs. Cotopaxi Batac 16L Daypack
Two carry-on travel backpacks, compared spec for spec.
STM Prime
| Capacity | 15 L |
| Weight | 0.7 kg |
| Dimensions | 42×26×13 cm |
| Airline fit | 96% |
| Price | $80 |
Feature by feature
| STM Prime | Feature | Cotopaxi Batac 16L Daypack |
|---|---|---|
| Storage | ||
| N | Compression | N |
| None | Expanded Capacity | None |
| 0 | Opening | 0 |
| top | Passport | top |
| N | Passthrough | N |
| Carry | ||
| Y | Backpack | Y |
| N | Hip Belt | N |
| Y | Sternum Strap | Y |
| Inside | ||
| 13in | Laptop | N |
| 2 | Main Compartments | 3 |
| N | Organizer | N |
| Outside | ||
| × | Hard Shell | × |
| N | Rain-fly | N |
| 2, side | Water Bottle Holder | 2, side |
| Y | Water Resistant | N |
| Material | |
| Polyester | 100% deadstock nylon & polyester |
Cotopaxi Batac 16L Daypack
| Capacity | 16 L |
| Weight | 0.3 kg |
| Dimensions | 48×28×10 cm |
| Airline fit | 93% |
| Price | $70 |
Key differences between the STM Prime and Cotopaxi Batac 16L Daypack
- Laptop sleeve: 13in on the STM Prime; No on the Cotopaxi Batac 16L Daypack.
- Main compartments: 2 on the STM Prime; 3 on the Cotopaxi Batac 16L Daypack.
- Water resistant: Yes on the STM Prime; No on the Cotopaxi Batac 16L Daypack.
Both have: passport pocket, backpack straps, sternum strap, water bottle pockets.
Which airlines take each bag as a carry-on
We checked both bags against the carry-on size limits of 189 airlines. 176 accept both. 5 accept only the STM Prime, and 0 accept only the Cotopaxi Batac 16L Daypack.
Only the STM Prime fits
Air Tahiti, American Eagle, easyJet, Gulf Air, Ravn Alaska.
STM Prime vs. Cotopaxi Batac 16L Daypack: which should you pack?
The Cotopaxi Batac 16L Daypack carries 1L more than the STM Prime (15L vs. 16L), while the Cotopaxi Batac 16L Daypack is the lighter pack at 0.3kg (vs. 0.7kg). For carry-on flexibility, the STM Prime fits 96% of the airlines we track — the higher of the two. If you prioritise packing volume, choose the Cotopaxi Batac 16L Daypack; if you want to travel lighter, the Cotopaxi Batac 16L Daypack is the better call.