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Quick answer
For most one-bag travelers, a 35–40 liter backpack that opens like a suitcase is the sweet spot. Based on our research: the Osprey Farpoint 40 / Fairview 40 is a strong all-rounder, the Peak Design Travel Backpack 45L is the most adjustable (but heavy), the Cotopaxi Allpa 35L has excellent organization, and the Matein Travel Laptop Backpack is a budget option for short trips.
How we chose
Research-based, not hands-on tested. We compared manufacturer specifications against common airline size limits and read published expert reviews for recurring strengths and weaknesses. How we choose gear.
Comparison table
| Backpack | Best for | Size (maker) | Capacity | Weight | Laptop | |
|---|---|---|---|---|---|---|
| Osprey Farpoint 40 / Fairview 40 | All-round one-bag travel | 21.7 x 13.8 x 9.1 in | 40 L | 3.27 lb / 3.23 lb | Up to 16 in | Check price |
| Peak Design Travel Backpack 45L | Adjustable capacity, photographers | 22 x 13 x 9.5 in (11 in expanded) | 30 / 35 / 45 L | 4.5 lb | Up to 16 in | Check price |
| Cotopaxi Allpa 35L | Organization, suitcase-style packing | 22 x 12 x 10 in | 35 L | 2 lb 15 oz | 15 in | Check price |
| Matein Travel Laptop Backpack | Budget, short trips, personal item | 18 x 12 x 7.8 in | 28 L | 1.68 lb | 15.6 in | Check price |
Swipe the table sideways to see all columns.
What to look for in a travel backpack
Size: 35–40 liters for carry-on
Capacity in liters is a rough guide; the external dimensions are what airlines check. Many US airlines allow 22 x 14 x 9 inches. Note that the Cotopaxi Allpa is 10 inches deep by Cotopaxi’s figures, which can matter on strict airlines if it’s packed full.
Clamshell opening
A backpack that unzips fully like a suitcase is much easier to pack and live out of than a top-loading hiking pack.
Harness and hip belt
If you’ll carry the bag for more than a few minutes at a time, padded shoulder straps and a hip belt make a big difference. Stowable straps help when checking the bag or sliding it into an overhead bin.
Laptop access
A separate laptop compartment you can reach without opening the main section speeds up airport security.
Weight
Feature-rich bags often weigh 4 lb or more empty. If your airline weighs carry-ons, a lighter bag leaves room for clothes.
Our research-based picks
Osprey Farpoint 40 / Fairview 40
Best for: Most one-bag travelers who carry their bag between stations, hostels and hotels
Why it stands out: A 40-liter carry-on-sized pack with a stowable harness and hip belt, lockable main zippers and a laptop sleeve, backed by Osprey's All Mighty Guarantee. Fairview is the women's-specific fit.
- Size21.7 x 13.8 x 9.1 in
- Capacity40 L
- Weight3.27 lb (Farpoint), 3.23 lb (Fairview)
- FabricRecycled 210D/420D nylon
- LaptopUp to 16 in
- WarrantyOsprey All Mighty Guarantee
What we like
- Harness and hip belt zip away
- Light for a 40-liter travel pack
- Separate men's and women's fits
Keep in mind
- Reviewers note limited interior organization
- No extra capacity beyond 40 liters
Peak Design Travel Backpack 45L
Best for: Travelers who want one bag that compresses for flights and expands at the destination, including photographers
Why it stands out: It compresses to 30 L, sits at 35 L as a standard carry-on and expands to 45 L, and opens from the front, back and sides.
- Size22 x 13 x 9.5 in (11 in deep expanded)
- Capacity30 / 35 / 45 L
- Weight4.5 lb
- FabricRecycled 400D nylon canvas
- LaptopUp to 16 in
- WarrantyLifetime guarantee
What we like
- Very flexible capacity
- Access from multiple sides
- Works with Peak Design's packing and camera cubes
Keep in mind
- Heaviest pack in this guide at 4.5 lb
- Expensive, a common criticism in published reviews
- Expanded depth exceeds the 9 in norm
Cotopaxi Allpa 35L Travel Pack
Best for: Organized packers who like suitcase-style compartments in a backpack
Why it stands out: It opens fully like a suitcase with mesh compartments, has lockable anti-theft zippers and stowable straps, and weighs under 3 lb by Cotopaxi's figures.
- Size22 x 12 x 10 in
- Capacity35 L
- Weight2 lb 15 oz
- Fabric840D TPU-coated recycled nylon
- Laptop15 in
- WarrantyLifetime warranty and repairs
What we like
- Suitcase-style opening and compartments
- Lockable zippers
- Light for its size
Keep in mind
- 10 in depth is over the common 9 in carry-on norm
- Reviews of the previous version noted limited water resistance; Cotopaxi now sells an updated model
Matein Travel Laptop Backpack
Best for: Weekend trips, business overnights, or as a personal item alongside a carry-on
Why it stands out: A light 28-liter laptop backpack with a separate 15.6 in laptop compartment that opens flat for security and a USB pass-through port.
- Size18 x 12 x 7.8 in (15.6 in version)
- Capacity28 L
- Weight1.68 lb
- MaterialWater-resistant polyester
- Laptop15.6 in
- WarrantyLifetime if registered within one month (maker)
What we like
- Very light
- Laptop compartment opens 90–180 degrees
- Small enough to work as a personal item on many airlines
Keep in mind
- Not a full one-bag travel pack: no clamshell main compartment or hip belt
- We couldn't find a detailed expert review to confirm long-term durability
Common mistakes
- Buying a 50–60 liter hiking pack for carry-on travel. It’s usually too big and top-loading.
- Ignoring empty weight on airlines with carry-on weight limits.
- Overstuffing the expansion zip so the bag no longer fits the sizer.
FAQ
What size backpack can I take on a plane?
For a carry-on, many US airlines allow up to 22 x 14 x 9 inches. Personal-item limits are smaller and vary widely, so check your airline.
Is a travel backpack better than a suitcase?
It depends on where you’re going. Read travel backpack vs suitcase for a full comparison.
Final recommendation
Start with the Osprey Farpoint 40 or Fairview 40 if you want a proven all-rounder. Choose the Peak Design 45L if adjustable capacity matters more than weight. Pair any of them with packing cubes and our carry-on packing method.
Travel rules, prices and product details change. Check official government, airline and manufacturer sources before you book or buy.
