There are quite a few different types of keto-friendly condiments. Most mustards, for example, contain few, if any, carbs, so they are keto-friendly. Lots of different hot sauces are also made with little to no sugar, and the fact that you generally only use a little at a time will help to keep your carb consumption low. While most commercial mayonnaise is not keto-friendly, there are brands of mayo that are low in carbs and can be a great part of your keto diet.