What soft drink has the least amount of caffeine?

Among common soft drinks, caffeine-free options like caffeine-free Coca-Cola or caffeine-free Diet Coke have no caffeine. However, if considering caffeinated drinks, root beers, such as A&W and Barq's, typically contain very low levels of caffeine compared to colas. In general, most lemon-lime sodas, like Sprite, are also caffeine-free.