Why a keto label can still hide carbs
A front-of-pack claim like "sugar-free" or "keto" tells you less than the ingredient list on the back. Manufacturers use dozens of carbohydrate ingredients that do not read as sugar, mostly to add bulk, sweetness or texture. Maltodextrin is the classic example: it is made from starch, digests quickly, and is the main bulking ingredient in many zero-calorie sweetener packets. Modified food starch thickens sauces and dressings. Rice syrup and glucose syrup sweeten bars that advertise no cane sugar.
This checker reads the list the way an experienced label-reader would: it matches each ingredient against a list of sugars, starches and sugar alcohols, ranks what it finds by how much it is likely to count, and tells you where each one sits in the list.
How to read the results
Sugars and starches count fully toward net carbs. Sugar alcohols are split in two: maltitol, sorbitol, isomalt, lactitol and xylitol have a measurable effect on blood glucose (published glycemic index values from about 6 for lactitol to about 35 for maltitol), so subtract about half; erythritol has a glycemic index of about 0 and is subtracted in full. Low-impact ingredients such as allulose, stevia, monk fruit and inulin add little or nothing, though stevia and monk fruit products are often bulked with something that does count.
Position matters because US ingredient lists run from heaviest to lightest. A sugar in the first three ingredients is a different product from one where dextrose appears after "contains 2% or less of". To turn the label into grams, use the net carb calculator.
Two safety notes
Xylitol is highly toxic to dogs, even in small amounts, so keep xylitol-sweetened foods and gum out of their reach. And a 2023 observational study linked high blood levels of erythritol with a higher rate of cardiovascular events; that is an association, not proof that erythritol causes harm, but it is reasonable to keep sweetener-heavy foods occasional rather than constant.
What this tool does not do
It does not know quantities, so it cannot tell you whether a product fits your day; only the Nutrition Facts panel can. It only recognizes the ingredients on its list, and labels outside the US may use different names. Nothing you paste is stored or sent anywhere.