These are the crispiest keto onion rings you'll ever find! They are ready in just 15 minutes and make a tasty appetizer, side dish or snack. Includes frying pan method, air fryer method and oven method.

Crispy onion rings are always on top of the list when I have a "junk food" kinda day. Even before I started a low carb diet, I'd reach for onion rings over French fries. They are just so much more interesting!
I think you'll love this keto onion rings recipe. It goes perfectly with keto chicken nuggets, keto hot dogs or burgers (check out my black burger buns!).
I decided to make them the old school way by deep-frying them for superb crispness.
This batter tastes very similar to one made with wheat flour because it uses my secret ingredient - whey protein isolate. It is super-fine and becomes incredibly crispy - much more than any almond flour coating!
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🌟 Why You'll Love This Recipe
- Incredibly crispy texture
- Authentic flavor
- Naturally gluten-free
- 3 cooking methods - pan-fry, air fryer and oven
- keto friendly - only 3.3g net carbs per portion
Ingredients
Here are the ingredients you will need:

- Onions - I use yellow onions because they are lowest in net carbs.
- Whey protein isolate - This should be unfavored whey protein.
- Seasoning - It's essential to use a good amount of spices to flavor the breading mixture. I like garlic powder, paprika, sea salt and black pepper.
- Egg - Just like for any regular breading, the egg is necessary to bind the breading with the onion.
- Dijon mustard - In my opinion, this tastes better than yellow mustard.
- Sparkling water - There is something about carbonated water that makes the breading lighter and crispier than if you used regular water.
- Avocado oil, ghee or coconut oil to fry. All of these oils have a high smoke point. Another option would be to use a light olive oil.
See the recipe card for full information on ingredients and quantities.
Variations
There are various types of gluten-free batters and breading. The most common coatings are almond flour, coconut flour or pork rinds plus seasonings.
For a variation, try these keto bread crumbs instead of the whey protein mixture. This breading contains almond flour, parmesan cheese and my secret ingredient - ground flaxseed. It is super crispy.
Instructions
This section contains step by step instructions and photos that show how to make the recipe.

Step 1: Slice the onions into rings.
Step 2: Place all the dry ingredients in a shallow bowl and mix. Add the wet ingredients to another bowl and mix to combine.

Step 3: Dip each onion ring in the egg mixture and then into the dry mixture to fully coat them with the breading.
Step 4: Heat the oil in a large pan until hot and bubbling. The oil should be deep enough to fully cover the onion rings.
Step 5: Carefully lower the onion rings into the hot oil and fry about 45 seconds or until golden brown and crisp.

Step 6: Remove the rings with a slotted spoon and place on a paper towel to soak up any excess fat. Repeat until all rings are fried.

Expert Tips
Here are my top tips how to make the recipe perfectly.
Coating: Use one hand for the bowl with the dry mixture and the other hand for the bowl with the wet mixture. That way, your hands won't get sticky and messy.
Frying: Coat 8 rings at a time and fry in batches of 4 to avoid the batter soaking and disappearing into the egg.
Recipe FAQs
Spray the breaded onion rings with cooking spray and air fry at 180C / 350F for 8 minutes or until the top is browned. Then flip them over with a spatula and air-fry for a further 8 minutes or until fully crisp.
The most important thing is to keep the rings in a singer layer so the air can circulate around. If you have a smaller air fryer, you'll need to cook them in 2 batches.
Yes, but they won't be as crispy as with the deep-fried or air fried method. To bake low carb onion rings, preheat the oven to 200C / 400F. Line a baking pan with parchment paper and arrange the onions in a single layer, not touching each other.
Spray them generously with oil and bake for about 10 minutes or until the tops are golden. Flip over and bake for another 10 minutes or until the keto breading is golden all over.
I don't recommend it. The rings go soft when stored. Also, they need to be fried straight after breading or the whey protein powder will go soggy.
Onions are are suitable for a keto diet in moderation. Since an average whole onion contains 11 grams of net carbs, it's important to keep the portion size low.
Regular onion rings are not keto friendly. They are coated in wheat flour, cornflour or breadcrumbs. These keto onion rings are the perfect solution for a low carb diet.

Dipping Sauces
Onion rings taste even better with a dipping sauce!
Serve them with homemade sugar free ketchup, keto mayonnaise or sugar free sweet chili sauce.
They also taste great with ranch dressing or a blue cheese dressing. For a bit of kick, choose this sriracha aioli.
Storage
Refrigerator: Keto onion rings are best fresh. If you have leftovers, store them in an airtight container in the fridge for up to 2 days. They will go soft.
Reheating: To crisp them up again, reheat in the air fryer or in the preheated oven at 200C / 400F for about 5 minutes.
The recipe is not suitable for freezing.
Related Recipes
Here are more veggie based keto appetizers to try:
- Keto Zucchini Fries40 Minutes
- Cauliflower Popcorn45 Minutes
- Keto Spinach Balls30 Minutes
- Low Carb Keto Falafel40 Minutes
Tried this recipe? Give it a star rating below!
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Recipe

Keto Onion Rings
Video
Ingredients
- 120 g onions actual onion rings - 3 onions (170g) and I discarded the ends and tiny bits in the middle
DRY
- ½ cup whey protein powder isolate, 50g
- ¾ teaspoon garlic powder
- 1 teaspoon paprika
- ½ teaspoon flaked salt
- ¼ teaspoon black pepper
WET
- 1 large egg
- 1 teaspoon dijon mustard
- 1 tablespoon sparkling water
- Oil to fry. Avocado ghee or coconut are best. I used 2 cups.
Instructions
- Use a fork to steady the onion. Slice into 1 cm rings. Remove the skin and separate the rings. Discard the ends and the small rings right in the centre.
- Heat the oil in a 18 x 9 cm saucepan until really hot and slightly bubbling. The oil should be deep enough to fully cover the onion rings. I used 2 cups.
- Place all the dry ingredients in a bowl and mix. Add the wet ingredients to another clean bowl and mix to combine. Dip each onion ring in the wet and then into the dry to fully coat and place on a wire rack. Coat 8 at a time and fry in batches of 4 to avoid the whey batter soaking and disappearing into the egg.
- Carefully lower 4 onion rings at a time into the hot oil and fry about 45 seconds or until golden and crisp. Remove the onion rings with a slotted spoon and place on kitchen paper to soak up any excess fat.
- Repeat for all the remaining onion rings.











Shirley
Can you use Hemp Protein plus fiber powder?
Katrin Nürnberger
I’m not sure what fibre powder is. But what I would say is that whey protein has a mild taste than hemp protein. Swapping the protein powder will change the flavour.
JT
Can you use a bone broth protein instead of whey. Examples: Equip or PaleoValley protein powders.
Katrin Nürnberger
No, collagen powder is not going to work. It becomes too soft when you add liquid.
Shirley
Can you use plant based organic protein powder instead of whey? Thank you.
Katrin Nürnberger
This would change the taste and I am not sure you'd like it. I have tried both pea protein and hemp protein and both have distinctive flavors (you can taste the nuttiness/the legume).
Beth
OMG Keto Onion Ring recipe....where have you been all my life!!!!! I have tried to make onion rings before, even regular ones when I was not keto, and never thought any of them came out really well; until now! They are so light and crunchy, even my teenage son who is not doing keto though they were really good. I don't have a air fryer, so I did them on the stovetop in about 1/2 - 3/4 inch of avacado oil. Flipped 1 time then set on paper towel to absorb excess oil. Added a splash of buttermilk to egg mixture, and some white pepper too whey mix for a little more kick. Only thing that stinks (literally) is that oil smell kind of permeates your house for 24 hrs. But TOTALLY worth it!!!! BEST ONION RING Recipe ever! Cannot wait to try more recipes from you <3
Katrin Nürnberger
Haha, what a success!
Kelloggs
I'm curious. 45 seconds doesn't seem like it would be long enough to soften the onion. Are the onions softened or still crisp (not the batter, I mean the actual onion)?
Katrin Nürnberger
Mine were just on the right side of soft.
Anita Sue
Sub for sparkling water? I never use it. Would plain water work?
Katrin Nürnberger
It would probably work, but I have not tried it.
Dale
I "cut" fruit juices with Club Soda. I will use Club Soda here - pretty sure it will work fine. Club Soda is cheaper than juice by far, so by adding about 25% it not only cuts the cost of juice but also the sugar content. Maybe having a secondary use for Club Soda will solve your issue with this recipe,