Yes, Coke Zero does have caffeine.
While often compared to Diet Coke, Coke Zero contains caffeine, although typically a slightly smaller amount. A 12-ounce can of Coke Zero contains 34 mg of caffeine, according to Tasting Table. This is less than the 46 mg found in the same size can of Diet Coke.
In conclusion, if you're looking to avoid caffeine, Coke Zero isn't the right choice. However, it has slightly less than Diet Coke.
