Answer: Tofu is low carb, but opinion is split about its keto-friendliness.
Tofu is a controversial food in the keto community. Most varieties of tofu are low in carbs, ranging from 2-8 g net carbs per serving. Tofu is very popular with vegan/vegetarian keto eaters.
Some keto experts recommend against tofu, as it contains soy, and there is evidence that soy is not a healthy food for humans.