Pepsi Zero vs. Diet Pepsi​: Here’s the Difference

I’m a veteran of the Cola wars. I remember when “Diet” emerged as the new word attached to low-calorie sodas, and when the preferred label shifted to “Light,” as in Pepsi Light. Don’t get me started on Pepsi Free, the caffeine-free version that Marty McFly tries to order in Back to the Future, only to have the 1955 diner employee tell him he has to pay for it. (And he can’t run a Tab, either. That’s 1985 soda humor.)

But now, the hip descriptor for diet sodas is “Zero,” as in Coca-Cola Zero Sugar and Pepsi Zero Sugar. What’s interesting is that both Coke and Pepsi also have Diet Coke and Diet Pepsi, plus Coke Zero and Pepsi Zero. In short, they’re making customers choose between two similar zero-calorie drinks.

Are Diet Pepsi and Pepsi Zero different?

Diet Pepsi and Pepsi Zero have slightly different ingredients and tastes. Last year, I taste tested Diet Coke and Coke Zero and compared the ingredient lists. They were not too different from each other. Kind of like siblings with different hairstyles. And I found the same thing with Diet Pepsi vs. Pepsi Zero.

Both Diet Pepsi and Pepsi Zero contain carbonated water, caramel color, aspartame, phosphoric acid, potassium benzoate, caffeine and citric acid. The ingredients aren’t listed in exactly the same order. For example, aspartame is the third ingredient in Diet Pepsi and the fourth in Pepsi Zero. Diet Pepsi also lists the sweetener acesulfame potassium, which is not in Pepsi Zero. Pepsi Zero lists calcium disodium EDTA, a food additive that is used to preserve flavor, color and texture, while Diet Pepsi doesn’t.

According to YouTube personalities Rhett and Link, who did a massive soda taste test, “diet sodas typically use aspartame as the fake sugar, while ‘zero sugar’ sodas use acesulfame potassium along with a few other artificial sweeteners.”

But what does all that mean when it comes to taste? Of course, I had to try both.

Diet Pepsi vs. Pepsi Zero Taste Test

Diet Pepsi has a silver can and Pepsi Zero a black can, which is useful to know if you’re trying to find them on your grocer’s shelves. Both have the round red, white and blue Pepsi logo. The words “Zero Sugar” are so small on that product that it’s easy to mistake it for regular Pepsi, until you realize that the sugar version comes in a bright blue can.

Just as I did with Diet Coke and Coke Zero, I chilled cans of both Diet Pepsi and Pepsi Zero and poured them into glasses without ice, so they wouldn’t be diluted. When poured out, both have the same rich caramel color and are just a bit fizzy.

Which one is best?

I put the two colas in different-shaped glasses so I could tell them apart and sipped from them alternately as I watched Monday Night Football. I soon noticed that I kept reaching for Pepsi Zero over and over rather than Diet Pepsi.

For me, Pepsi Zero is by far the better of these two Pepsi choices. It tastes smoother and richer, and it’s more thirst-quenching.

Diet Pepsi isn’t terrible. It has a spicier aroma and an almost tangy taste compared to Pepsi Zero. It’s OK on its own, but I don’t love it with food. If I need a cola to wash down a handful of chips or something, Diet Pepsi kind of stabs at my throat, not going down as easy as Pepsi Zero.

You should be able to find both Pepsi Zero and Diet Pepsi wherever Pepsi products are sold. You can even mix one of the colas with a protein shake for Pepsi’s version of the viral protein Diet Coke. And keep an eye out for the upcoming Pepsi Wild Cherry and Cream flavor, arriving in January with a zero sugar option!