With the correct cap, YETI's are 100% leakproof.u003cbr/u003eUnfortunately, a magslider cap is not leakproof. A tipped mug or bottle will leak slowly. The beverage doesn't gush out. I've recovered a dropped mug or tumbler more times than I'd like to remember. A fairly quick recovery is always possible with little loss of beverage.u003cbr/u003eu003cbr/u003eThe leakproof versions are generally screwed in. These are indeed 100% leakproof but require more work to access your drink.u003cbr/u003eu003cbr/u003eYETI has done a phenomenal job of providing options so you can choose the right bottle for you. By that, I mean what drink, where you consume it, how you carry and how long it needs to stay insulated.