Yes, WhatsApp, FaceTime, and other video/voice calling apps work perfectly fine over mobile data and Wi-Fi throughout Thailand.
Thailand does not impose any restrictions on Voice over IP (VoIP) services, meaning you can freely use popular communication apps like WhatsApp, FaceTime, Line, Zoom, and Google Meet to make calls and video calls. As long as you have a stable internet connection, either via your eSIM's mobile data or a local Wi-Fi network, your calls will connect normally. An eSIM ensures you have reliable data coverage to support these applications by automatically connecting to the strongest available major network in Thailand. The exact network provider your eSIM connects to may vary depending on your specific plan, but you can expect consistent connectivity for all your communication needs.