A 12-ounce (355 ml) can of Diet Coke contains approximately 46 mg of caffeine. This amount is higher than the caffeine content in a regular Coke, which has about 34 mg per 12-ounce can

. The caffeine in Diet Coke is added to give it a distinctively more acidic and slightly bitter flavor compared to regular Coke

. To summarize:

• Diet Coke (12 oz): ~46 mg caffeine
• Regular Coke (12 oz): ~34 mg caffeine

This caffeine content is significantly less than that found in coffee, which typically contains about 95 mg per 8-ounce cup