Red and green Thai chillies usually come from the same plant. Green chillies are picked early, while red ones are left to ripen. Green chillies taste sharper and more herbal, and red chillies are slightly sweeter and fruitier. How hot a chilli is depends more on its variety than its colour, so a ripe red chilli can be just as fiery as a green one. Both are at the heart of Thai cooking, from curry pastes to stir-fries and dipping sauces.
At a glance
Red vs green: usually the same chilli at different stages of ripeness
Green chillies: sharp, fresh and herbal, with an immediate heat
Red chillies: slightly sweeter and fruitier, with a rounder, lingering heat
Heat: Thai bird’s eye chillies are typically 50,000–100,000 Scoville Heat Units
Used in: curry pastes, stir-fries, garnishes and dipping sauces
Thai Chillies: A Diverse Family of Heat
There isn’t just one “Thai chilli”. Thailand grows dozens of chilli varieties, which vary in size, shape and colour. Most share one trait: plenty of heat. Small but very pungent, Thai chillies are essential to the bold flavours of Thai cooking.
The Chilli Pepper Plant
Chilli peppers are the fruit of plants in the nightshade family (Solanaceae), alongside tomatoes, aubergines and potatoes. Most Thai chillies belong to the species Capsicum annuum or Capsicum frutescens. Their heat is measured in Scoville Heat Units (SHU), a scale based on how much capsaicin (the compound behind the heat) they contain:
Sweet bell peppers: 0 SHU
Jalapeños: about 2,500–8,000 SHU
Thai bird’s eye chillies: about 50,000–100,000 SHU
Habaneros: about 100,000–350,000 SHU
Inside the pod, the tiny white or cream seeds are attached to the pale inner membrane, which holds the most capsaicin.
Red vs Green Thai Chillies
Red and green Thai chillies usually come from the same plant. The difference is ripeness: green chillies are harvested early, and red chillies are left to ripen fully.
Green Thai chillies have a sharper, more herbal flavour, and their heat hits straight away. They’re perfect for quick dishes like stir-fries.
Red Thai chillies are slightly sweeter, with a rounder, more mature flavour. Their heat tends to build and linger, which suits curries and slow-cooked dishes.
Both can be used fresh, dried or ground into powder. Thai cooks often combine them, balancing the bright, sharp heat of green chillies with the deeper warmth of red.
How Thai Chillies Are Used in Cooking
In Curry Pastes: Chillies are the backbone of Thai curry pastes, pounded or ground with aromatics like garlic, lemongrass and galangal. Fresh green chillies give green curry its colour and bright heat, while red curry paste is made with red chillies. Traditionally, green curry is often the hotter of the two, but it depends on the recipe. Our Red Curry Paste (3/5) is actually a little hotter than our Green Curry Paste (2/5). Read why in Which Is Hotter: Red or Green Thai Curry?.
In Stir-Fries: In quick stir-fries, fresh Thai chillies are often sliced thinly and added towards the end of cooking for a burst of heat. Dishes like pad kra pao (stir-fried holy basil) rely on fresh bird’s eye chillies to balance the savoury flavours of garlic and sauce.
As Garnishes: With their bright colours, Thai chillies are often used as a garnish, sliced or whole, adding colour and signalling the heat to come. You’ll often see them on top of soups like Tom Yum and curries like Panang, where they stand out against the creamy coconut sauce.
In Sauces and Dips: Thai chillies are key to traditional sauces like nam pla prik: fish sauce, lime juice and thinly sliced chillies. This simple, punchy sauce is served alongside many Thai meals to add extra heat and seasoning.
Are Thai Chillies Good for You?
Fresh chillies contain vitamin C and capsaicin, the compound that gives them their heat, which researchers continue to study. Most of us only eat a few chillies at a time, so think of them mainly as a way to add big flavour without needing extra salt or fat.
How to Handle Thai Chillies Safely
Thai chillies are high in capsaicin, so handle them with care:
Wear gloves if you’re preparing a lot of chillies, as capsaicin can irritate your skin.
Don’t touch your face, especially your eyes, and wash your hands well afterwards.
For less heat, remove the seeds and the pale inner membrane before cooking.
Frequently Asked Questions
Are red and green chillies the same?
Usually, yes. Most red and green Thai chillies are the same chilli at different stages of ripeness. Green ones are picked early, and red ones are left to ripen on the plant.
Are green chillies hotter than red?
Not necessarily. Heat depends more on the variety than the colour. Green chillies taste sharper and their heat hits faster, while red chillies are sweeter, with a heat that lingers.
How hot are Thai chillies?
Thai bird’s eye chillies are typically 50,000–100,000 Scoville Heat Units, much hotter than a jalapeño.
The Power of Thai Chillies
Red and green Thai chillies are much more than a source of heat. Their sharp, fruity flavours and bright colours make them essential in Thai cooking, whether you’re making a fiery curry, a quick stir-fry or a simple dipping sauce. Next time you’re in the kitchen, reach for these small but mighty chillies and bring bold flavour and colour to your cooking.
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From Jum’s Kitchen
In Thailand, the tiniest, fiercest chillies are called prik kee noo, literally “mouse-dropping chilli”. The name is affectionate rather than crude: a nod to their size and their punch, and a reminder that in Thai cooking, small doesn’t mean insignificant. Fresh Thai chillies bring brightness as well as heat. Green chillies have a sharp, almost grassy edge that cuts through rich coconut milk, and red chillies are warmer, sweeter and more patient. Once you taste the difference, it’s hard to go back.
If you’re new to fresh chillies, start with one or two and build from there. Thai food isn’t about proving you can handle the heat. It’s about balance. Our curry pastes are stone-ground the traditional way, so the heat sits naturally in the dish instead of burning for the sake of it.
