The Best Carry-On Backpack Review & Roundup

We love to travel with only a carry-on backpack - it lets us keep all of our important stuff within reach, save money on checked baggage fees, and helps us get in and out of the airport faster than the 99% of people that are miserably lugging around multiple bags. 

carry on only backpack

Of course, we use our expandable Knack Packs whenever we travel, because we believe that our Knack Pack’s have better organization, functionality, and appearance than any bag out there. Traveling with a Knack Pack means that we can open up our bag mid-flight and pull out exactly what we’re looking for, without spilling the contents all over the airplane floor. 

The craziness of the holidays makes it the best time of year to travel with only a carry-on, so this week we’re sharing what makes Knack Pack the very best carry-on backpack for travel (and work), with reviews from real Knackpackers.

Read this: How to save money on holiday travel

What makes a great carry-on bag:

. It meets airline carry-on requirements.

. It’s easy to find your stuff on the plane.

. It can hold everything you want and serve as the only bag you need.

The expandable travel compartment

The problem with many bags is that they don’t change to fit your needs. They’re either too big to get on the plane or they’re too small to carry everything you need for your trip. That’s why we developed Knack’s patent-pending, hidden suitcase compartment that expands when you need it and zips away when you don’t.  

This unique compartment gives you extra room for a few day’s worth of clothes, while still meeting the carry-on requirements of most airlines (even the Large Knack, at 46 liters expanded, is still within the carry-on requirements for almost all airlines). And because all Knack Packs’ travel compartment opens like a suitcase, you get great ease of access.

“Starts light, grows as needed, great pocket organization/segmentation with a unique look that doesn’t get lost in the overhead. I’m 6’ 4” and the bag is comfortable (not too big or small). A winner.” - Jeremy B., Medium Series 2

Here's how much extra space (in liters) the expandable compartment gives you with each Knack Pack size:

 Small Series 1 15L unexpanded + 12L = 27L
Medium Series 1 27L unexpanded + 12L = 39L
Large Series 1 30L unexpanded + 16L = 46L
Medium Series 2 24L unexpanded + 11L = 35L
Large Series 2 30L unexpanded + 16L = 46L

I bought this for a carry-on bag and to use on weekend trips…. I fit 2 pairs of jeans, a pair of dress pants, a dress shirt, 4 t-shirts, and underwear and socks in the suitcase area. All of my medications and toiletries fit into the main compartment and I still had room for more stuff if needed. The zippers are sturdy and I like the look of my bag. I can't wait to use it more! I also found the expandable packing cases to be very useful. - Paula, Large Series 1

What's the best size of backpack for travel? Find out here

expandable backpack

Pockets that give everything a place

While airplanes can be a great place to get some work done, it’s hard to get motivated to pull out your laptop, charger, and headphones when they’re buried deep in a carry-on with your clothes, toiletries and travel gear. 

But with a separate compartment for everyday items and loads of well-placed pockets, Knack Packs make it easy to know exactly where your work stuff is. Keep your laptop in the padded side-access laptop pocket, your headphones in the mesh pocket in the everyday compartment, and your tablet in its own dedicated fleece-lined pocket.

On the Series 1 Knack Pack, quick-access pockets are located on the outside of the bag - including a phone/sunglasses pocket, a bottom cable garage, and our iconic double-zippered pocket which is awesome for an e-reader or administrative tools. 

Conversely, the Series 2 Knack Pack moved the S1’s quick-access pockets inside the bag for a more streamlined exterior look. But on both bags, all the things that you need regular access to are always readily accessible, so you don’t have to dive deep into the bag to get what you’re looking for (and even if you do have to dig something out, our bright antimicrobial lining will help). 

“There are so many pockets and flaps to keep all of your stuff organized. I love how the main compartment opens up fully. It allows you to get to all your clothes easily without messing up your fold jobs on the clothes you haven’t used yet.” - Chris B. - Series 1 Medium

And since Knack Packs’ everyday compartment is separate from its travel compartment, if you need to pull out another sweatshirt mid-flight, you don’t need to rearrange your entire backpack. 

“I've used it for a couple of week long trips now, and it is wonderful. I love that the compartment for clothing and essentials is separated from where I keep my business essentials and tablet, so I can get to what I need without tossing boxers and socks everywhere.” - Travis M., Series 2 Medium

Can fit under the seat in front of you

Sometimes you want to travel light, but your bag is too big to fit under the seat in front of you - which means that you’re either forced to carry a smaller second bag, or you have to dig into the overhead compartment throughout your flight. 

The Small and Medium Knack Packs fit under the seat in front of you on most jets even when expanded, and the Large Knack Pack can fit when unexpanded. The advantage of not needing to use the overhead bins is best described by Knackpacker Matt S.:


  • Dragging their carry-ons around the airport
  • Worrying about overhead bin space
  • Immobile

     Me and my Knack:

    •  Walking onto the plane last minute, not worried about bin space;
    • Freedom to explore;
    • Happiness” 
      - Matt, Series 1 Medium

      Of course, when you stick a backpack on the airplane floor, you want to be sure that it’s not going to get all scuffed-up. That’s why Knack Pack has a custom, abrasion-resistant fabric that’ll hold up to whatever you put your Knack down on. And with thoughtfully placed exterior handles, you can easily pull your Knack out from under the seat in front of you. 


      “Needed to organize. I really needed to have an organized carry-on and this is it!!! This backpack was easily organized for a portable office at my destination and for what I wanted during travel: airport/plane. I love it!! I could not believe how easily it fit under the seat. Thank you Knack!” - Adina G.

      Read this: An Ultimate Guide to One-Bag Business Travel

      When you need more than just a carry-on bag

      Although Team Knack lives dedicated One Bag lives, we sometimes find ourselves needing to travel with a checked bag and a carry-on. So we designed all Knack Packs with a hidden trolley sleeve that slips over the handle of your wheeled luggage. You can wheel your Knack around the airport in a truly compact fashion, especially when you take advantage of the stow-away shoulder straps.

      Ready for holiday travel? Find the best carry-on bag for your trip with this super helpful comparison chart

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