Long story short, sriracha may or may not be vegan.
It depends on how strict of a vegan you are.
To understand why, we need to look at the ingredients in the original Huy Fong Sriracha sauce.
Sriracha Sauce Ingredients
Here are its the ingredients in the “real” sriracha:
INGREDIENTS: Chili, sugar, garlic, salt, distilled vinegar, potassium sorbate, sodium bisulfite, and xanthan gum
Most of those are clearly vegan, except the sugar.
Some sugar is vegan, and some is not. It depends on whether or not it was processed with bone char (from cow bones).
Read the link above for a look at the issue. But the conclusion is that a significant chunk of sugar is made using bone char and isn’t vegan.
That being said, some vegans don’t think it’s practical to avoid sugar, and don’t worry about this. You’ll have to decide for yourself.
Unfortunately, when only “sugar” is listed on the ingredients list, we have no way of knowing if it’s vegan or not.
That means that the original Sririacha sauce may or may not be vegan-friendly.
It’s up to you if you’re okay with taking that risk.
What About Other Sriracha Sauces?
If you’re buying a “sriracha” sauce that is made by a different company, it may or may not be vegan.
These sauces often have similar, but different ingredients. Common non-vegan additions are fish sauce and shrimp paste.
Carefully check the ingredients of any close alternatives before buying.