For dimensions, while they don't routinely measure the dimensions of checked bags there is a size limit. If it's a little bit over you may get lucky and the airline won't notice but you're taking a chance with it.

Yes, in 2026, airports and airlines have become significantly stricter about checking baggage dimensions, often moving away from human discretion in favor of automated gate sizers and AI-powered scanners. While legacy carriers like Delta and American may still rely on gate-agent observation for "obviously" oversized bags, low-cost carriers like Spirit, Frontier, Ryanair, and easyJet are known for aggressive enforcement. These airlines often have metal sizer boxes at the gate and will require you to fit your bag inside; if it doesn't fit—including wheels and handles—you will be charged a "gate-check fee" which can range from $60 to $100. Even if you aren't pulled aside at the gate, many 2026 airports are testing "smart bins" at security checkpoints that automatically flag bags exceeding the standard 22 x 14 x 9 inch limit. International travelers should be especially careful, as European and Asian carriers often enforce even smaller dimensions and strict weight limits (usually 7kg to 10kg) that many US-marketed "carry-ons" frequently exceed.