Which diet soft drink has the most caffeine?
                                
                                
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                                    3 min read                                
                            
                                According to the Center for Science in the Public Interest, a 12-ounce can of Zero Sugar Mtn Dew contains approximately 68 mg of caffeine. While many people assume diet sodas have less caffeine, the truth is that their stimulating properties vary widely across brands and formulations. This variance makes it important to check labels and compare products to know exactly what you're consuming.