Xylitol generally isn’t advisable on the ketogenic diet, as it still spikes your blood sugar levels.
Xylitol is found in small amounts in many fruits and vegetables and is therefore considered natural. Humans even produce small amounts of it via normal metabolism.
It is a common ingredient in sugar-free chewing gums, candies, mints, and oral care products.
Instead, I would recommend Erythritol or Stevia.