Copycat In-N-Out Sauce

Die-hard In-N-Out lovers like me would like to make one thing clear: Thousand Island dressing is not the same as In-N-Out sauce. For two decades I called Los Angeles home, and In-N-Out isn’t just a fast-food chain—it’s a love language. And if you know, you know. The secret menu? It’s practically a rite of passage. From animal style everything to the glorious Neapolitan shake, you feel as if you’re part of an insider club whenever you order something not on the board. But let’s be honest—no matter what you order, it’s that In-N-Out burger sauce (we call it the spread) that ties it all together.

Whether a late-night snack while driving down Sunset Boulevard or a sunny afternoon treat on Venice Beach, the first taste of the sauce is pure magic—creamy, tangy and just the right amount of sweetness. Some may call it a condiment, but for us West Coast devotees, it’s a lifestyle.

While I may have traded palm trees for the magic of the Midwest, my heart (and taste buds) are forever loyal to Double-Doubles, animal style fries and that legendary spread. And now with one of our favorite copycat In-N-Out recipes, you can channel a little West Coast magic at home. Whip up this copycat In-N-Out burger sauce recipe, throw on your shades and take a bite out of a classic—no drive-thru line or secret handshake required!

Ingredients for Copycat In-N-Out Sauce

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• Mayonnaise: Where other fast food restaurants also have special sauce, this spread is all about the mayo. Use a high-fat, good-quality mayonnaise for this recipe to ensure you build a solid foundation for the rest of the flavors. This is a great time to make homemade mayonnaise.
• Ketchup: Where classic Thousand Island dressing uses chili sauce, In-N-Out burger sauce leans into the sweet and sassy pop of tomato flavor that ketchup offers.
• Sweet pickle relish: Sweet pickle relish adds a burst of tangy sweetness and a little crunch. It’s like a tiny flavor bomb that transforms your sauce from “meh” to “oh wow!”
• White vinegar: The zesty disrupter, white vinegar cuts through the fatty richness with a sharp tang that wakes your taste buds. It’s the ingredient you don’t notice but would miss if it weren’t there.
• Sugar: A pinch of sugar is the balancing force of this flavor mashup. It cuts through the vinegar’s tang and enhances the sweetness of the ketchup and relish.

How to Make Copycat In-N-Out Sauce

Step 1: Mix it up

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Combine the mayonnaise, ketchup, sweet pickle relish, white vinegar and sugar in a bowl.

Editor’s Tip: No need to get fancy with a blender or food processor; a good spatula will do the trick.

Step 2: Chill out

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Cover the sauce and let it chill in the refrigerator for at least one hour.

Editor’s Tip: Keeping it cool means the ingredients can meld into a gorgeous symphony of flavor.

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In-N-Out Sauce Variations

• Add some spice: Sriracha or chili oil gives just a touch of heat and, while not strictly In-N-Out canon, adds an exciting flavor element.
• Try Worcestershire sauce: Umami vibes are always welcome in my kitchen, and Worcestershire sauce adds a magical little twist to the spread.
• Include mustard (maybe?): Shhhhh! Don’t tell the serious In-N-Out hardliners, but a little mustard is a dynamite addition. When you get a Double Double Animal Style, they fry the burger with mustard on one side so the flavor fuses with the beef patty. You can try that, too, or take the easy way and add a little squirt to the sauce.

How to Store In-N-Out Sauce

Store your copycat In-N-Out burger sauce in an airtight container or jar with a secure lid to keep it fresh. Refrigeration is a must, as the mayo-based mixture needs to stay cool. When you pull it out to use, give it a quick stir and you will be ready to go.

How long does copycat In-N-Out sauce last?

This sauce will stay fresh in the fridge for about five days. Keep it covered and stored at a consistent temperature to maintain its quality. If it starts to separate or have an off smell, it’s time to make a new batch.

Copycat In-N-Out Sauce Tips

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How can you use copycat In-N-Out burger sauce?

Of course, the most obvious recommendation is to use In-N-Out sauce on a burger or as a topping for a fresh pile of fries, but don’t limit yourself. This sauce is a workhorse on things like a fresh garden salad or a baked potato, or even as a substitution for tartar sauce at your Friday fish fry.

Use it on grilled cheese sandwiches, classic Reuben sandwiches, turkey clubs and tacos. This copycat sauce works just about anywhere you’d use mayonnaise, ranch or Thousand Island dressing for dipping or drizzling.

When it comes to deviled egg variations, copycat In-N-Out sauce adds the flavor and tanginess that people crave. Mix the yolks with a generous spoonful of the copycat sauce instead of plain mayo, add a pinch of salt and pepper to enhance the flavor, and pipe or spoon the mixture into the egg whites. Garnish with a sprinkle of smoked paprika or finely chopped chives for a pop of color.

What’s the best mayo to use for In-N-Out burger sauce?

Full-fat mayonnaise is best for providing the creamy richness that defines this sauce. Some of the best mayonnaise brands, like Hellmann’s, Duke’s or Best Foods, are ideal for authentic flavor and texture. If you’re looking for a healthier option, you can use light mayo, but the sauce won’t be quite as luscious.