This is hands-down the healthiest and most flavorful low carb tomato sauce recipe in the entire world. With a few simple ingredients, you too can make this versatile, nutritious, and delicious pasta sauce! The best part is, it’s an insanely easy recipe.

7 Reasons This is The Best Recipe
While there are plenty of low carb marinara sauce recipes floating around, ours is the best for a few key reasons:
- Simple, every day ingredients
- Only takes 30 minutes to make
- Can use fresh, whole tomatoes or canned tomatoes
- No added sugar
- Keto-friendly, gluten-free and vegan
- Simple to store in the fridge or freezer
- Versatile sauce! Use to make keto pizza, keto lasagna, etc.

Pasta la vista, baby
My gorgeous, Italian-born Uncle smuggled in a killer marina sauce recipe when he moved to the States. Besides tasting like something out of The Godfather, I was surprised that the recipe is naturally low-carb.

How? Carbs come from sugar, and this recipe has very few. And there’s no need to add sugar because there are enough healthy natural sugars in tomatoes to begin with.
This begs the question…are tomatoes low in carbs?
Are Tomatoes Naturally Keto Friendly?
Yes, tomatoes are a low-carb fruit, which makes them an ideal addition to any low-carb diet! Organic tomatoes have 4 net grams of carbs and 2 grams of natural sugar per serving size (half-cup).

Tomatoes are also incredibly nutritious. They’re rich in fiber and are packed with potassium, folate, vitamin K, and vitamin C.
Is store-bought tomato sauce keto-friendly? Regarding mass-manufactured pasta sauce, brands like Ragu average 12 net carbs per 1/2 cup serving, while homemade sauce has less than 4.
No Added Sugar or Preservatives
Why does this homemade tomato sauce taste different from the store-bought kind? It all comes down to added sugar and preservatives present in most pasta sauces found in the grocery store.

If you want to make your sauce a bit sweeter while keeping it keto-friendly, you can add sugar alternatives such as liquid monk fruit extract, Stevia, or Swerve.
How To Make This Low Carb Tomato Sauce Recipe:
This recipe is simple, inexpensive, nutritious, and delicious. All you need are a few basic ingredients, and you’re good to go. This recipe makes about ten half cup servings of sauce.

Ingredients
This is all you need to make this tomato sauce. Feel free to substitute the oregano and basil for Italian seasoning if you have that on hand.
- 5-6 medium organic diced tomatoes
- 1 medium onion
- 6 garlic cloves (minced or crushed)
- 2 tbsp Olive Oil
- 1 tbsp Oregano (dried or fresh)
- Salt and pepper to taste
Optional Ingredients:
- Liquid monk fruit sweetener (sugar substitute)
- Crushed Red pepper flakes
- Basil (dried or fresh)
- 1 tbsp vegan butter
- Garlic powder (instead of garlic)
- Onion powder

Step 1: Saute Garlic & Onions
Heat 2 tablespoons of olive oil in a medium saucepan over medium heat. Toss in 1 chopped medium onion. Cook for 4-5 minutes until translucent.
Add the chopped garlic or minced garlic and cook for another minute or two.

Step 2: Add Tomatoes & Herbs
Add your diced fresh tomatoes, oregano, salt, and any other spices to the saucepan. Bring this mixture to a soft boil and then reduce the heat.
Simmer for 30 minutes or so. Now that your sauce has thickened, you can add some more fat (optional).

Step 3: Add Vegan Butter or Olive Oil (Optional)
This is an optional step. Adding fat at this stage helps to balance out any overpowering acidity from the tomatoes. I enjoy the flavor profile of the vegan butter.

Once you’ve added your fat, you can remove it from the heat.
Step 4: Blend The Sauce
I like a chunky sauce. However, if you prefer a smooth sauce, you can take the extra step of blending it. I’d recommend using an immersion blender, stand blender, or food processor.

Once blended, the color of the sauce will shift from dark red to a lighter, almost pink-red.

Garnish the sauce with some fresh chopped basil! All done!
Wait…Can I Eat Tomato Sauce on Keto Diet?
Yes. As mentioned at the top of this blog, tomatoes are a keto-friendly fruit since they have low net carbs per serving.

What Can I Use Instead of Sugar in Tomato Sauce?
If you’re used to a sweeter tomato sauce, like the store-bought kind, you can add a splash of natural sugar alternatives. Luckily, there are a lot of keto sugar substitutes on the market.

Here’s a list of the best sweeteners to use on a low-carb keto diet:

Can I Add Other Ingredients To My Sauce?
Yes, of course. Just keep everything low carb. Add tomato paste to your sauce to make it a bit richer tasting. Add ground beef or Italian sausage if you want to make this into a keto-friendly meat sauce.
How Do I Store My Tomato Sauce?
Store your tomato sauce in the refrigerator in an airtight container, and it’ll last about a week.
You can also freeze your tomato sauce. I recommend using a freezer-safe bag or a FoodSaver bag. Frozen pasta sauce, if sealed tightly, will last anywhere from 3 – 6 months.
What to Serve With Low Carb Tomato Sauce?
Pasta! If you want to really watch your carbs, substitute spaghetti squash, zucchini noodles (zoodles), or low-carb pasta for your pasta. I like this brand of low-carb pasta made from chickpeas.

This sauce is perfect for dipping your keto-friendly breadsticks and keto mozzarella sticks into. You can also use this as a low carb pizza sauce.
Use this with any of your existing keto recipes on your low carb diet, and you won’t be let down!
The Recipe

Easy Keto Low Carb Tomato Sauce Recipe
Ingredients
- 6 medium tomatoes - chopped
- 1 medium onion - finely chopped
- 6 garlic cloves - minced or crushed
- 2 tbsp Olive Oil
- 1 tsp Dried Oregano
- 1 tsp Cracked red pepper flakes
Optional Ingredients
- 1 tbsp Vegan butter
- 1 tsp liquid monk fruit sweetener
- 1 tsp basil
- 1 tsp Garlic Powder
- 1 tsp Onion Powder
Instructions
- Saute Garlic & OnionsHeat 2 tablespoons of olive oil in a medium saucepan over medium heat. Toss in 1 chopped medium onion. Cook for 4-5 minutes until translucent. Add the chopped garlic or minced garlic and cook for another minute or two.1 medium onion, 6 garlic cloves, 2 tbsp Olive Oil
- Add Tomatoes & HerbsAdd your diced fresh tomatoes, oregano, salt, and any other spices to the saucepan. Bring this mixture to a soft boil and then reduce the heat. Simmer for 30 minutes or so.6 medium tomatoes, 1 tsp Dried Oregano, 1 tsp Cracked red pepper flakes
- Blend The SauceI like a chunky sauce. However, if you prefer a smooth sauce, you can take the extra step of blending it. I’d recommend using an immersion blender, stand blender, or food processor.Garnish the sauce with some fresh chopped basil! All done!
Your Own Notes
Video
Nutritional Information
The Golden Lamb provides nutritional information, but these figures should be considered estimates, as they are not calculated by a registered dietician.
Love it? Pin it! Share on FacebookThanks for stopping by! I’d love to hear from you in the comments below. What did you think about this low carb spaghetti sauce recipe? Would you consider this a great recipe? Why or why not? I’d love to hear from you. Bon Appetit!
While you’re here, please try one of my fantastic recipes!
- Lemon & Butter Rock Fish Fillet Recipe
- Cheesecake Recipe Without Sour Cream
- Giblet Gravy without Giblets
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