Is it the same sausage as sai krok Isan?
No. Sai ua is a grilled Northern sausage with herbs. Sai krok Isan is an Isan dish made by fermenting pork and rice, and its tangy flavor from fermentation is its trait.
Sai Ua · ไส้อั่ว
If you want a fragrant meat dish in Chiang Mai, pick sai ua. It is a Northern sausage made by mixing chilies and herbs into pork and grilling it. One bite gives you the savory taste of grilled meat and the aroma of herbs together. With sticky rice and vegetables, it makes a satisfying Northern Thai meal.

The savory flavor of pork is joined by herbs and chili seasoning. Its distinctive aroma is different from the sausages you are used to. The heat depends on the recipe, so if you are trying it for the first time, start with a small piece.
It is a sausage of pork mixed with herbs and grilled.
Sai ua often appears on the table of the Lanna North. It is also eaten with sticky rice or with dipping sauces such as nam prik. Order it with nam prik ong, which is seasoned with tomato, and vegetables, and you can alternate between the grilled meat and the sauce.
No. Sai ua is a grilled Northern sausage with herbs. Sai krok Isan is an Isan dish made by fermenting pork and rice, and its tangy flavor from fermentation is its trait.
The typical sai ua is made with pork. If you do not eat pork, it is better to choose another dish for your meal.
If you want to read more about the food and the regions behind it, these sources are a good place to start. Ingredients and recipes can vary from one restaurant to the next.
Sharing image credit: Takeaway · CC BY-SA 3.0