Can a Laos tourist extend their 30-day stay in Thailand or must they exit and re-enter?

@Rossano **************

it's not only for Laos citizens. It's for everyone that receives visa waiver through bilateral agreement. The entry days vary from 15-90 based on the agreement these countries have with Thailand.

There is no limit written into law. Citizens of neighboring countries likely have much more leeway to leave and return than others.