Uber has officially pulled out of Southeast Asia and removed its service in Thailand since April 2018. Instead, most travelers and local residents use Grab, which is by far the biggest online transportation network company in the region.
We always recommend travelers download Grab before visiting Southeast Asia. It’s both comfortable and convenient to jump into a clean car, without the necessity of communicating with the driver and experiencing detours.
Just keep in mind that the prices are determined by supply and demand. Thus, prices can be high during rush hours and in the multiples during events such as New Year’s Eve. As such, it’s not always a preferred choice to use Grab over regular taxis (if you want to save money, that is).