Hat Yai is a beautiful city in Southern Thailand with a large number of Muslim population. So, finding halal food and prayer room in Hat Yai should not be a problem. There are plenty of halal food and Mosque or prayer room around the city.
For me, Hat Yai is a great place to visit in Thailand. The authentic Thai halal street food is one of the reasons. Well, i believe that many travelers are already familiar with Lee Garden, Asean Market, Greenway Shopping and Klonghae Floating Market areas for the halal street food. But, there is also a place that not many travelers actually know. This is a place that is very popular with locals.