I read on https://immigration.go.th/content/visa_auto_extension (mirror):
👮♂️ The person whose visas has expired from 26th of March 2020 will be automatically extended to 30th of April 2020. There is no need to apply for a visa extension at Immigration Office for this period and will not be fined THB 500 per day for this case.
Does the COVID-19-related automated visa extension till the 30th of April 2020 also apply to foreigners who entered Thailand visa-free?
I have crossposted the question at: