The short version
Ask r/onebag for a 40L bag and the Osprey Farpoint 40 (or the Fairview 40, its women's-fit twin) gets named in almost every thread. That's not marketing. It's a decade of people carrying it through airports and reporting back. The suspension is a real backpack harness with a padded hip belt, which matters more than any feature list once you've walked two miles from a train station with 18 pounds on your back.
The Farpoint is not the best-built bag at 40 liters. Cotopaxi and Tortuga owners will tell you the Osprey's fabric feels thinner and the straps dig if you overpack it. They're right. But those bags cost $200 to $300. The Farpoint sits around $185, carries better than both when loaded, and Osprey's All Mighty Guarantee means they'll repair it for as long as you own it.
If $185 is too much
The Amazon Basics Carry-On Travel Backpack, usually around $50, is the bag people sheepishly admit they bought and then kept using. It opens like a suitcase, has a padded laptop compartment, and several owners have posted after 10 or more trips with no failures.
Two honest caveats. There is no hip belt, so the whole load sits on your shoulders; that's fine for airport-to-hotel, tiring for a full day. And the interior lining is thin and slick; one owner said it "feels like it will rip just by touching it," though the same owner noted it hadn't. Treat it as a bag you might replace in three years, not thirty.
Why not the others
- Cotopaxi Allpa 35L (around $200): better organization and more durable shell. The recurring complaint is that you have to open the entire bag to grab anything, and the harness is less comfortable on long walks than the Osprey's.
- Tortuga Travel Backpack 40L (around $300): probably the best build of the group. It's also nearly twice the Farpoint's price, and Reddit's consensus is that the difference is nice, not necessary.
- Tomtoc Navigator 40L (around $130): a newer favorite with strong reviews, but not enough multi-year owner reports yet to call it proven.
- Cheap "40L" no-name bags at $25 to $35: many run small, zippers are the usual failure point, and returns are a hassle. Spend the extra $15 on the Amazon Basics.
Which one for you
Trips longer than a week, or lots of walking between stops: Farpoint 40. Weekend trips and airport-to-Uber travel where the bag mostly rides in an overhead bin: the Amazon Basics is genuinely enough.