The VISA EXEMPTION RULE allows tourists from 64 countries to enter Thailand without a VISA. They are granted to stay a maximum of 30 days if they are entering Thailand via an international airport or entering through a land border checkpoint from neighboring countries.
64 Countries allowed to enter Thailand under the VISA EXEMPTION RULE.

Click here for more info: https://www.thaiembassy.com/thailand-visa/thai-visa-exemption-and-bilateral-agreement