In 2026, the answer depends entirely on your baggage choice and the specific technology at the airport. For carry-on luggage, the global standard remains the 3-1-1 rule: you cannot bring a full-size shampoo bottle (typically 8–12 oz) unless it is in a container of 3.4 ounces (100ml) or less. However, some major international hubs have upgraded to advanced Computed Tomography (CT) scanners, which in theory allow for larger liquids, but the "100ml limit" is still legally enforced by most aviation authorities like the TSA and EASA to maintain consistency. If you must travel with your favorite full-size bottle, it must be packed in your checked luggage, where there are no volume restrictions for non-hazardous toiletries. For a more sustainable and hassle-free 2026 alternative, many travelers have switched to shampoo bars (solid form), which are not subject to liquid restrictions at all and can be carried in any size in your cabin bag.