This post may help those that are considering which backpack to choose when deciding between Tom Bihn’s Synapse 25 and Synapse 19.

Looking at the specs, it is obvious which bag is bigger.

S25 dimensions: 20″ x 13.4″ x 9″ / 508 x 340 x 230 mm; Volume: 25 liters (1526

S19 dimensions: 16″ x 11.4″ x 7.9″ / 410 x 290 x 200 mm; Volume: 19 liters (1160

So how much of a difference is there in real world situations?

Here are the items being packed:

  • Lenovo L440
  • Dell XPS 13 (in TB Cache)
  • iPad Air
  • iPad mini
  • Notebook
  • Cables and Power brick in Freudian Slip
  • Klean Kanteen 27oz
  • Cookies (not pictured; used bottom compartment on both S19 & S25)


It doesn’t look a lot does it?

First up is the S19:


Now with the S25:



Maybe the pictures does really show it but the S19 was literally packed to the fullest. It was actually hard to get everything into the main compartment. You can really tell the bulge on the S19 when compared to the S25. The S25 definitely had everything in the backpack with LOTS of room to spare.

While the S19 was tight, it was still able to hold everything pictured. Obviously it is never ideal to have 2 laptops but it could happen. For me I have a work laptop and a personal laptop and sometimes I want to bring both to get things done work-wise and school/personal-wise.

For school I might just say S25 over S19 because you never know what you will need to pack. The S19 is a great EDC, it can still do school, work, hike and travel, but I still prefer a bit more space.

I want to also point out that the Freudian Slip for the S19 and S25 are different as well. I like the S25 version a lot more because it has zippers that can hold more things securely. I may do a separate post regarding that.

Hope this post helps you guys out there deciding which to get.

Note: the 2 side compartments and the middle small compartment was not utilized.