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Keto Tomato Spaghetti Sauce

Keto Spaghetti Sauce is a great recipe to make because it is quick, easy, and super simple. It can be used on top of your favorite pasta dish, lasagna, pizza, meatballs…etc.

Easy Low Carb Pasta Sauce

It is also a delicious marinara sauce for dipping some of your favorite foods into, like mozzarella sticks, fried zucchini, or eggplant, and chicken tenders.

I have always loved making tomato sauce since I was young. It was one of the first things that my mother taught me how to make. 

How you want to use the low carb tomato sauce will depend on whether you make it with meat in it which cooks all day, or a simple version like this keto spaghetti sauce that is ready quickly. 

Store-bought jarred sauce is ok to eat on a Keto diet, but making your own is super easy to do and it comes out much more flavorful to eat. We love putting on top of low carb noodles or zucchini noodles!

Why is this the Best Spaghetti Sauce? (Tomato Sauce)

This keto spaghetti sauce is the best sauce to use when you are looking for a fresh taste without any added sugar or carbs.

Making your own keto marinara sauce is so much better than using store-bought jar sauce and can go from start to finish in only 30-45 minutes, which makes it a terrific quick dinner over low carb pasta on a weeknight after working all day.

Spoonful of Keto Spaghetti Sauce

You can start with canned tomatoes, either whole, diced, or crushed, then add your favorite spices. We all love garlic and onions, they add so much flavor. You don’t even have to take time to chop them…just use garlic powder and onion powder. 

Then add one or more of your favorite green seasonings such as basil, parsley, and oregano and that’s it.

Tomatoes on Keto

You may wonder if you can eat tomatoes on the keto diet since they are not really a vegetable but are a fruit. Tomatoes have high water content and are a very low carb fruit, so if you are counting your carbs feel free to add them to your list of acceptable foods to eat.

  • A large whole tomato has only 5 net carbs.
  • A medium whole tomato has 3.3 net carbs.
  • A small whole tomato has 2.5 net carbs.

Small varieties, such as cherry, and grape, can be enjoyed as a great snack or part of a meal because they only have 4-5 net carbs per 1 cup. 

Sun-dried tomatoes have so many more carbs in them, similar to other dried fruits. For ½ cup of sundried tomatoes, it is 12 net carbs, which would be too many for a low carb diet, unless you only eat a few at one sitting.

Carbs in Tomato Sauce

Tomato sauce is also relatively low in carbs. Once the tomatoes cook down into a canned or jarred variety, they are only about 4.7 NET Carbs for ½ cup as long as you do not add any sugar to it, and that’s perfect for a low carb/keto diet.

Keto Marinara Sauce

A lot of jarred sauces have added sugar which pushes it out of the low carb category.

Sugar is hidden in a lot of the foods that we are used to eating, such as cereal, protein bars, yogurt…etc. All of these are foods that you would think are good for you, so you need to check labels before eating things to make sure that the carbs are not too high.

When looking at labels of store-bought tomato sauce, they have an average of 8-12 grams of sugar per ½ cup, which translates into about 10 carbs.

What to Serve with Low Carb Tomato Sauce?

Meatballs covered in Keto Spaghetti Sauce

Low carb spaghetti sauce can be used in a lot of recipes as a main ingredient or for dipping. Here are a few suggestions:

What Ingredients are in Keto Spaghetti Sauce?

  • Tomatoes – Canned tomatoes, whole, chopped, or crushed are all good choices to use in sugar-free spaghetti sauce. Fresh tomatoes will work too.
  • Parsley – Fresh or dried will both do the trick.
  • Basil – Fresh or dried will be good in the low carb pasta sauce. 
  • Salt – This enhances the flavors of food, but it is not necessary if you have a blood pressure problem and can’t use salt in your diet.
  • Pepper – Ground black pepper. If you like spicy food, then feel free to add crushed red pepper instead.
  • Garlic Powder – This is my favorite spice and used in a lot of foods, including most Italian recipes. If you would prefer, you could use fresh or jarred garlic.
  • Onion Powder – You can never go wrong with adding onion flavor to keto tomato sauce too. If you want to, dried onion flakes or even fresh chopped will be good too.
Keto Spaghetti Sauce ingredients

Best Tomatoes to Use

When you make keto marinara sauce, it’s best to use tomatoes from a can. They can be whole, chopped, or crushed. 

My favorite type of canned tomatoes are San Marzano if you can find them in your grocery store. But any brand of tomatoes will work. They are more costly, usually 2-3 times more than other types of tomatoes, but if you can afford them they are Italy’s favorite!

My other choice of tomatoes is the Tuttorosso brand, and I use the crushed variety, which is the perfect texture for sugar-free tomato sauce. 

You can also use ripe, fresh tomatoes to make keto pasta sauce if you prefer. We talk about it in more detail later on in the recipe, under the heading “how to pick out tomatoes.”

Different Variations of Low Carb Marinara Sauce

You can vary the ingredients in your sugar-free spaghetti sauce and try different things. That way it’s like eating a different sauce every time.

Here are some of the ingredients you can add to get a different flavor sauce:

  • Meat: Add a number of different meats such as ground beef, ground pork, ground sausage
  • Veggies: Carrots, celery, onions, mushrooms, bell peppers ( red, orange, yellow, green)
  • Red Pepper: for a spicy sauce
  • Type of Tomato: Whole tomatoes, crushed tomatoes, fresh tomatoes, canned tomatoes
  • Cheese: Parmesan, Romano
  • Cream: Add some heavy cream to make your low carb tomato sauce creamy.
  • Texture: Make it chunky or smooth by the texture of your tomatoes.
  • Butter Sauce: Add 1 or 2 Tbsp butter to the keto pasta sauce.
Keto Marinara Sauce and fried zucchini

Other Low Carb Pasta Sauces

If you don’t want a tomato-based sauce, here are some other low carb options to put on pasta:

  • Alfredo Sauce – A creamy white sauce
  • Oil & Garlic Sauce – The name speaks for itself…good olive oil and fresh chopped garlic
  • Pesto Sauce – Fresh basil and cheese made into a yummy sauce
  • Arrabiata Sauce – A spicy sugar-free tomato sauce
  • Vodka Sauce – Along with vodka there is cream, butter, tomatoes, and onion
  • Bolognese/Meat Sauce – A low carb pasta sauce mixed with onions and meat


It can be confusing to pick out the right tomatoes to make your keto spaghetti sauce with, so we will give you a few ideas.

Fresh Tomatoes

If you are looking for real juicy tomatoes get tomatoes on the vine or any other similar type. Make sure that they are bright red, which means they are ripe, rather than pale in color which means they are not ripe. 

If the fresh tomatoes are ripe then they will make a sweeter sauce with a lot more flavor. If the tomatoes are not ripe enough then the low carb marinara sauce will be tasteless.

Summertime is the best time to buy fresh tomatoes, especially if you have a garden. There is nothing like picking tomatoes right in your backyard and coming in the house and making something with them…you can’t get any fresher than that and they will make the freshest tasting keto tomato sauce.

If you use fresh tomatoes to make low carb pasta sauce, they will have to be blanched first to get the skins off, then chopped up, and cook them down until they reach the desired texture.

Plum tomatoes are too dry and will not give you the consistency that you need. They have a firm texture and are better to be used as sliced tomatoes on top of pizza since they will not make your pizza soggy.

Best Keto Tomato Sauce

Canned Tomatoes

When you use canned tomatoes, the best type is San Marzano, which usually comes whole in a light tomato sauce. They are the top choice in Italy. They are typically more expensive than other canned tomatoes that you can buy, so look for a sale. 

There are other types of canned tomatoes that come in a thin sauce, petite diced, regular diced, and crushed.

And then there is tomato paste which is very concentrated and used to thicken your sauce if that’s the way that you want it.

Best Store-bought Low Carb Tomato Sauce

In my opinion, Rao’s is the best store-bought sauce and the closest thing to homemade keto pasta sauce. They have several varieties, all of which are low carb spaghetti sauces:

  • Marinara
  • Arrabiata Sauce
  • Vodka Sauce
  • Bolognese Sauce
  • Tomato Basil Sauce
  • Roasted Garlic
  • Garlic Alfredo
  • Margherita Pizza Sauce 
  • Alfredo 

It’s good to always have a few keto pasta sauces at home for a quick, no fuss, low carb dinner. The downside to always buying jar sauces is that they are certainly more expensive than making keto spaghetti sauce yourself. 

Here are a few store-bought brands of low carb pasta sauce 

  • Rao’s Marinara – ½ cup 100 calories, 7 grams fat, 420 grams sodium, 5 net carbs, 2 grams protein
  • Victoria Marinara – ½ cup 70 calories, 4 grams fat, 420 grams sodium, 5 net carbs, 2 grams protein
  • Prego No Sugar Added, Traditional – ½ cup 110 calories, 4 grams fat, 50 mg sodium, 7 grams carbs, 11 grams protein
  • Thrive Marinara – ½ cup 70 calories, 4 grams fat, 400 mg sodium, 5 net carbs, 2 grams protein
  • Cucina Antica Tomato Sauce – ½ cup 35 calories, 1.5 grams fat, 240 mg sodium, 4 net carbs, 1 gram protein
  • Barilla Fire Roasted Marinara – ½ cup 45 calories, 0 fat, 430 mg sodium, 8 net carbs, 2 grams protein
  • Primal Kitchen Marinara – ½ cup 50 calories, 2 grams fat, 480 mg sodium, 7 net carbs, 1 gram protein
One pot and bowl of Keto Spaghetti Sauce

Tools to Use

It’s always good to have the proper tools in your kitchen to make your meals, the same is true when making keto marinara sauce. Make sure you have the following:

  • Saucepan 
  • Ladle or Spoon for stirring
  • Measuring Spoons

How to Make Keto Spaghetti Sauce

It is so easy to make keto spaghetti sauce and we will show you step by step how simple it is.

STEP 1: Open the cans of crushed tomatoes into a saucepan.

Ingredients for Keto Tomato Sauce

STEP 2: The next thing to do is to add the spices (parsley, basil, black pepper, salt, garlic powder, onion powder). There is no special order, so just add them and stir them in well.

STEP 3: Heat up the sauce on low-medium and stir every few minutes so that it doesn’t stick or burn.

Low Carb Spaghetti Sauce cooking on the stove

STEP 4: Keep cooking the low carb tomato sauce for 30 minutes. When it’s done take the sauce off the burner and enjoy it with your favorite foods.

Low Carb Spaghetti Sauce with tomato garlic and black pepper

Best Tips

  • If you prefer a smooth sauce then use crushed tomatoes. and if you prefer a chunky sauce then use chopped tomatoes.
  • You can also use fresh tomatoes but you will have to blanch them first to remove the skins. 
  • If you want your keto pasta sauce to be smoother, and are using fresh tomatoes that have not been cooked down, then you could blend it with an immersion blender or in a traditional blender. 
  • Feel free to change up the spices in the low carb tomato sauce, try different ones to see what you like the best.
  • When using fresh garlic, use a garlic press, which is easy to use and will release the garlic taste when pressed.

Other Diets This Recipe is Good For

  • Vegan – This low carb marinara is only made from spices and tomatoes.
  • Vegetarian – No meat products in this sauce recipe, just tomatoes, and spices.
  • Paleo – This is a delicious low carb marinara sauce to put on many things.
  • Gluten-free – Only tomatoes and spices and no gluten products.
  • Dairy-free – There is no dairy in this keto spaghetti sauce.
  • Nut-free – No worries if you have a nut allergy, there are not any nuts.
  • Sugar-free – There is not any sugar in keto marinara sauce.
Best Keto Tomato Sauce

How to Store Tomato Sauce

To store keto tomato sauce if there is any leftover, put it into an airtight plastic container or a glass jar with a lid. It will last one week in the refrigerator, or if you are not going to use it right away then go ahead and freeze it.

If you are going to take the time to make something, you may as well make some extra which will save time later on when you are in a hurry to make dinner.

How to Reheat Marinara?

It is very easy to reheat your low carb marinara sauce.  You can reheat it in the microwave or in a saucepan on the stovetop. It will only take a few minutes.

Can You Freeze Spaghetti Sauce?

I freeze leftover low carb pasta sauce all of the time. Whenever I make any type of sauce, I always make more than I need so that I can have extra to freeze.

To Freeze: Keto pasta sauce will freeze the best when put into an airtight container and will keep good in the freezer for at least 6 months.

To Thaw: When you take it out of the freezer to use it, just thaw it out on the stove in a small saucepan slowly until it is all defrosted.

Keto Spaghetti Sauce on a spoon

Other Low Carb Sauce Recipes

If you’re in the mood for some other Low Carb Sauce recipes then try our:

They all are Keto-friendly and low carb, and will be a hit with your family and friends!

Keto Pasta Recipe
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Keto Marinara Sauce

Keto Tomato Spaghetti Sauce

  • Author: Leigh Oskwarek
  • Total Time: 40 minutes
  • Yield: 28 Servings (1/4 Cup Per Serving) 1x
Save Recipe


Keto Spaghetti Sauce is a great recipe to make because it is quick, easy, and simple to make. Low carb tomato sauce can be used on top of your favorite pasta dish, lasagna, pizza, meatballs…etc. It is delicious for dipping some of your favorite foods into, like mozzarella sticks, fried zucchini or eggplant, and chicken tenders.


  • 228 oz cans crushed Tomatoes (San Marzano)
  • 2 Tbsp dried Parsley
  • 1 tsp Basil
  • 1 tsp Black Pepper
  • 1 tsp Salt
  • 1 tsp Garlic Powder
  • 1 tsp Onion Powder




If you prefer a smooth sauce then use crushed tomatoes. and if you prefer a chunky sauce then use chopped tomatoes.

If you want your keto pasta sauce to be smoother, then you could blend it with an immersion blender or in a traditional blender. 

If you choose to use fresh tomatoes then you will have to blanch them first in order to remove the skins.

Feel free to change up the spices in the low carb tomato sauce, try different ones to see what you like the best.

When using fresh garlic, use a garlic press, which is easy to use and will release the garlic taste when pressed.

To Store: When storing the leftover keto spaghetti sauce be sure to put it in an airtight container or a glass jar with a screw on lid and refrigerate for up to a week.

To Freeze: If you have any leftover sauce feel free to freeze it for another time. You will appreciate it when you are in a hurry to make dinner and you already have your sauce made in the freezer. Just take it out and stick it in a saucepan to thaw it out. 

  • Prep Time: 10 minutes
  • Cook Time: 30 minutes
  • Category: Sauces
  • Cuisine: Italian

Keywords: Keto Spaghetti Sauce, Low Carb Spaghetti Sauce, Keto Tomato Sauce, Low Carb Pasta Sauce, Keto Pasta Sauce, Keto Marinara Sauce, Low Carb Marinara, Low Carb Tomato Sauce, Sugar Free Spaghetti Sauce, Sugar Free Tomato Sauce, Low Carb Marinara Sauce, Low Carb Italian, Keto Sauces, Best Keto Spaghetti Sauce, Best Keto Tomato Sauce, Easy Keto Tomato Sauce, Best Low Carb Pasta Sauce, Easy Marinara Sauce

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Thursday 28th of July 2022

This is definitely not keto. Keto threshold is 5%, and this recipe contains 80% calories from carbs. It's misleading to say the least :(

Leigh Oskwarek

Friday 29th of July 2022

Hi Auridas, I can understand what you are saying but this is a food that is not meant to be eaten by itself. A person does not just sit down and eat sauce without anything else. Adding veggies, or meat, balances out the protein, net carbs, fat, etc. to make the proper macros. The sauce is a good recipe when coupled with other things and can easily fit into the keto diet plan.