The four best personal-item backpacks that fit under US airline seats

I set out to find the best personal item backpack for my future travels and end the gamble once and for all. Photograph: Jessica Reyes/The Guardian

I love my REI Trail 40 Backpack. I’ve used it as my “personal item” on countless flights for nearly a decade. But, as a cost-conscious traveler, I always worry I will get caught for flying with an oversized personal item.

Almost every airline will let you bring a “personal item” aboard for free, so long as it can fit under your seat. Each airlines has specific measurements for a personal item. It’s especially important to mind these measurements on budget airlines such as Spirit and Frontier, which don’t offer carry-on bags for free. Purchasing a carry-on or checked bag on these airlines can drastically increase your flight cost, sometimes doubling the original price.