Question: what is the difference between coke zero and diet coke caffeine free?
Answer: The former also has slightly less caffeine at 34 mg in each can, compared to 46 mg in a can of Diet Coke. The main difference in the ingredient lists is Diet Coke contains citric acid, while Coke Zero Sugar does not, instead naming potassium citrate and an additional artificial sweetener called acesulfame potassium.