Best Keto Sodas & Prebiotic Sodas: Ranked by Net Carbs
The lowest-carb keto sodas are the zero-sugar diet colas and plain sparkling waters, which list 0 g net carbs per can, while prebiotic sodas like Olipop and Poppi add roughly 2 to 5 g net carbs once fiber is subtracted. Regular full-sugar soda runs about 39 g net carbs per can and doesn't fit a keto budget.
Soda is one of the easiest keto swaps to get wrong — not because the diet-soda aisle is short on options, but because "diet" and "zero sugar" aren't the same claim as "keto," and prebiotic sodas market their carb counts differently than a plain nutrition label would. This guide ranks the real net-carb math across the category, from truly zero-carb picks to the prebiotic brands that need a closer read, plus a DIY option if you'd rather skip labels altogether.
None of this is about finding a "healthy" soda — it's about finding the version that doesn't spend part of your daily carb budget without you noticing. A can of regular cola can use up an entire day's worth of net carbs on a strict plan in one serving, so knowing which swaps are genuinely 0 g and which just sound low-carb is worth the two extra minutes of label-reading. For how soda fits alongside every other drink category, see our keto drinks hub.
Which keto sodas have the fewest net carbs?
Diet and zero-sugar sodas built on non-nutritive sweeteners — Zevia, Diet Coke, Coca-Cola Zero Sugar, Diet Pepsi, Pepsi Zero Sugar, and plain sparkling waters like LaCroix or bubly — all list 0 g total carbohydrate per can, which means 0 g net carbs regardless of how tight your daily limit is. Figures below reflect each brand's published Nutrition Facts panel and, where noted, standard USDA nutrient references.4 The table ranks the category from zero-carb to avoid.
| Drink | Sweetener | Net carbs (12 fl oz) | Keto verdict |
|---|---|---|---|
| Zevia (all flavors) | Stevia leaf extract | 0 g | Best pick — zero-carb, zero-calorie |
| Diet Coke | Aspartame | 0 g | Keto-friendly |
| Coca-Cola Zero Sugar | Aspartame + acesulfame potassium | 0 g | Keto-friendly |
| Diet Pepsi / Pepsi Zero Sugar | Aspartame | 0 g | Keto-friendly |
| Plain sparkling water (LaCroix, bubly, etc.) | None — naturally flavored | 0 g | Best default; no sweetener debate |
| Olipop (prebiotic soda) | Cane sugar + allulose + fiber blend | ~2–5 g (varies by flavor) | Keto-friendly in moderation; check the label per flavor |
| Poppi (prebiotic soda) | Cane sugar + apple cider vinegar | ~4–5 g | Borderline — less fiber offsetting the sugar than Olipop |
| Regular cola (full-sugar) | High-fructose corn syrup or sugar | ~39 g | Not keto — avoid |
Zero-carb diet sodas
Every major diet or zero-sugar cola uses a non-nutritive sweetener — usually aspartame, sometimes with acesulfame potassium — in place of sugar, which is why the Nutrition Facts panel lists 0 g total carbohydrate and 0 calories.2 Zevia takes a different route, using stevia leaf extract instead of artificial sweeteners, but the net-carb result is the same: 0 g per can.
Sparkling water
Unflavored or naturally-flavored sparkling water (carbonated water plus natural flavor oils, no sweetener at all) is the simplest zero-carb option on this list and sidesteps the sweetener conversation entirely. It's the default "safe" choice if you'd rather not think about which sweetener you're drinking, and the flavor range — citrus, berry, cola, even root beer — is wide enough that "just sparkling water" doesn't have to mean one flavor forever.
Are prebiotic sodas like Olipop and Poppi keto-friendly?
Prebiotic sodas are not zero-carb — Olipop and Poppi both use real cane sugar plus a fiber blend, landing at roughly 2 to 5 g net carbs per can after fiber is subtracted, which can fit a standard keto carb budget in moderation but isn't the "basically free" drink the marketing sometimes implies. The gap between the front-of-can claim and the math on the actual Nutrition Facts panel is the thing to watch.
Net carbs are calculated as total carbohydrate minus fiber (and, by convention, minus non-impact sugar alcohols).1 A typical prebiotic soda can lists somewhere around 15 g total carbohydrate and 8 to 9 g fiber from a chicory-root or cassava-fiber blend, plus a few grams of added cane sugar — subtracting fiber the standard way puts net carbs closer to 5 to 6 g for some flavors, a little higher than a "2 g net carbs" callout printed on the front of the can. That's because some brands' front-label net-carb math also nets out allulose, a rare sugar that's technically counted in total carbohydrate but has a negligible effect on blood sugar and may be excluded from sugar declarations under FDA guidance.3 The takeaway: read the actual Nutrition Facts panel, not just the front-of-can number, and use the net-carb calculator to check a specific flavor against your own daily limit.
Poppi runs a similar model with less fiber per can than Olipop, so its net carbs tend to land at the higher end (4 to 5 g) even though both brands market themselves as "gut health" sodas. If you're tracking tightly, treat a prebiotic soda the way you'd treat any other 3 to 5 g net-carb item in your day, not as a free pour.
That's not a reason to avoid the category — a single can of either brand fits comfortably inside a standard 20 to 50 g keto carb budget alongside real food. It just means a prebiotic soda isn't interchangeable with a true 0 g diet soda on a strict under-20-g plan, where every gram is already accounted for.
What sweeteners should you watch for in keto soda?
The sweetener matters less for net carbs (all the options above are effectively 0 g) than it does for personal tolerance and long-term preference — aspartame, sucralose, acesulfame potassium, and stevia are the four you'll see most often on keto-soda labels, and none of them raise blood sugar or add meaningful carbs at typical serving sizes. For the full rundown on how each sweetener behaves, which ones some people are more sensitive to, and how sugar alcohols fit into the picture, see our guide to keto-friendly sweeteners.
If you're building out a broader keto grocery list, our keto food list covers where drinks fit alongside every other category.
How do you make keto soda at home?
A DIY keto soda is plain or flavored sparkling water plus a few drops of a liquid stevia or monk fruit extract, adjusted to taste — no added sugar, no mystery ingredients, and 0 g net carbs every time. It's the cheapest way to get soda-style fizz without relying on a packaged brand at all.
A simple starting ratio: fill a glass with unflavored sparkling water or seltzer, add 3 to 5 drops of a liquid stevia or monk fruit extract, a squeeze of fresh lemon or lime, and stir. Swap the citrus for a splash of sugar-free flavored syrup or a few muddled berries (checked against your daily carb budget) if you want more of a "craft soda" flavor. Because you control every ingredient, this is also the easiest way to avoid the sweetener debate above entirely.
It's also the cheapest fix if you're stocking a fridge for a household split between keto and non-keto eaters: one bottle of plain sparkling water and a bottle of extract covers several flavor combinations, instead of buying a different branded can for every preference.
Frequently Asked Questions
Can you drink soda on keto?
Are Olipop and Poppi keto-friendly?
Does diet soda kick you out of ketosis?
What's the healthiest keto soda?
How many net carbs are in Olipop?
Can I make keto soda at home?
Works cited
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