The serving sizes for both products (2 tablespoons) conveniently results in the carbs being zero (which just means less than 1). Carbs could be as high as 5%. The question is, is that a realistic serving size?
Tomatoes contain an unavoidable amount of sugar, so most tomato products, such as ketchup, cannot claim “sugar-free”. Apples, their ciders, and perhaps their vinegars, contain a lot of sugar, mostly free fructose. Corn starch is carbs. Splenda contains dextrose, in addition to any other concerns it raises.
In condiment quantities, these products don’t look that threatening. Our household prefers:
http://www.natureshollow.com/ecommerce/category/2:5/Sugar-Free-BBQ-Sauce
