They’re often used interchangeably, but there are some nuances.

• Red pepper flakes (crushed red pepper): Typically a blend of dried red chilies with some seeds. The mix can vary, so heat and flavor may differ by product.
• Chili flakes: Sometimes single-variety (like gochugaru, Aleppo, or Calabrian), often with fewer seeds and a more defined flavor profile.
• Flavor and texture: Blends lean spicier and punchy; single-origin flakes can be fruitier, smokier, or sweeter.

In most recipes, both can work. Start with a small amount and add more to match your preferred heat and flavor.

Several pantry swaps can stand in, depending on what you have and the flavor you want.

• Cayenne powder: Hotter and finer. As a rough start, use about 1/4 to 1/2 the amount of flakes, then adjust.
• Hot sauce: Adds tang and heat; splash in small amounts and taste as you go.
• Fresh chili: Mince and sauté for a fresh bite. Heat varies by chili, so add gradually.
• Aleppo or gochugaru: Milder, fruitier flakes that give warmth without as much burn.
• Chili oil: Great for drizzling; start with a small spoonful.

Heat levels vary across products, so add substitutes slowly and adjust to taste.

They bring heat differently, so they don’t swap one-for-one in every dish.

• Cayenne powder: Typically more concentrated and delivers a quick, sharp heat.
• Red pepper flakes: A coarser blend with seeds, giving a more variable, moderate heat and a crunchy texture.
• Swapping: If replacing flakes with cayenne, start with less powder and build up. If going the other way, you may need more flakes to reach similar heat.

Flavor and intensity can vary by brand and pepper variety, so tasting and adjusting is a practical approach.

You’ll most often see them labeled as “chilli flakes” in the UK (note the double “l”).

• Common terms: “chilli flakes” and “crushed chillies.”
• Regional styles: You might also encounter names like “pul biber” for Turkish-style flakes.
• Recipe notes: British recipes that call for “chilli flakes” generally mean the same ingredient used as crushed red pepper in the U.S., though heat can vary.

When browsing online, try those terms to find the style and grind you need.

Different flake styles shine in different dishes. Here’s a quick guide:

• Pizza and table seasoning: Classic crushed red pepper (coarser cut) for bursts of heat and texture.
• Chili oil and stir-fries: Evenly cut Sichuan-style flakes with fewer seeds for clean infusion, color, and controllable heat.
• Kimchi and Korean dishes: Gochugaru (coarse or fine) for gentle, sweet heat and vibrant color.
• Mediterranean dishes: Aleppo or similar styles for a milder, fruity warmth.

Check product details for grind size and heat notes. If you’re trying a new style, consider starting with a smaller quantity and adjust to taste.