If you're considering embarking on the keto diet, then you're probably familiar with the basics: it's a high-fat, moderate-protein, superlow-carbohydrate diet that puts your body into fat-burning state of ketosis. Since your carbohydrate count must be low, typically less than 50 grams a day, that means sugar is almost entirely off-limits.
However, you can enjoy some artificial sweeteners in moderation. This includes monk fruit, sugar alcohols, and yes, stevia. In fact, stevia is a key ingredient in many keto fat bomb dessert recipes. Although stevia has no calories or sugar, it still hasn't been approved by the FDA; rather, it is classified as "Generally Recognized as Safe," or GRAS. Substances categorized as GRAS means they are considered safe through scientific review or expert consensus, but are exempt from the rigorous requirements that would make it FDA-approved. Another issue with eating stevia is that since it's 200 times sweeter than sugar, it may lead you to crave more sugary foods and simple carbohydrates.
So yes, you can have stevia on the keto diet. Just make sure you enjoy it in moderation. In general, a well-formulated keto diet should be rich in whole, minimally processed foods such as leafy greens, nonstarchy vegetables, unprocessed meat, nuts, healthy oils, and full-fat dairy. If you need a touch of sweetness, such as in your coffee or for a keto bomb recipe, then powdered or liquid stevia can be used. But once you cut out sugar and use other keto-approved sweeteners only sparingly, you likely won't even crave it anymore.