Is Diet Coke Keto?

Yes — fits your limit

0g net carbs per 1 can (12 fl oz)

One serving is 0% of a 20 g day.

Recalculates as you change it.

0 g total carbohydrate − 0 g fibre = 0 g net carbs, against a 20 g daily limit — 0% of the day. We call it a fit at 25% of your limit or less, a maybe up to 50%, and a no above that.

Why

Aspartame is the sweetener. It contributes no carbohydrate, which is why every line on the nutrition panel reads zero.

On the only question this page is built to answer — does a serving fit your daily net carb limit — Diet Coke is a zero. It costs nothing against the budget. Whether it is a good idea is a separate argument about appetite, habit and taste adaptation, and honest people land in different places on it. We are not going to pretend the carb answer settles that.

Per labelled serving
Serving1 can (12 fl oz)
Total carbohydrate0 g
Fibre0 g
Sugars0 g
Protein0 g
Fat0 g
Energy0 kcal

We have not built this yet

Aisleful is a scanner that answers this question for any product in the shop, against the limit you actually keep to. It does not exist yet. If you would use it, say so — that is the entire reason this page has a button on it.

This form is not connected to anything yet — nothing you type here is recorded or sent.

Others people check

Common questions

Does Diet Coke break ketosis?
It contains no carbohydrate, so it does not spend your carb budget. Claims about insulin responses to non-nutritive sweeteners exist but the evidence is mixed; if you are tracking, test yourself rather than trust either side.
What about Coke Zero?
Same answer on carbohydrate — zero. The sweetener blend differs, and so does the taste.
Does it contain phenylalanine?
Yes. The label carries the phenylketonurics warning because aspartame contains phenylalanine.

Figures for this product come from the Open Food Facts community database, record 04965802, retrieved 2026-08-31. Open Food Facts is crowd-sourced and a record can lag the current package — treat the label in your hand as the authority. We publish the number and where it came from so you can check it.