Indonesia frequently experiences earthquakes and tsunami since Indonesia is geologically located in the ring of fire and sits along three major tectonic plates of the world thus this natural phenomena have the potential to continuously occur for example a notable tsunami that hit Aceh in 2004 and killed 160,000 people. This condition is not yet supported by adequate means of disaster mitigation and a tsunami early warning system. The objective of this study was to create an automatic tsunami early warning system that utilizes tsunami potential data from the Indonesian Agency for Meteorological, Climatological and Geophysics’ website to be conveyed through loudspeakers in places of worship whose area will be affected by the tsunami. This study used the Research and Development (RnD) method with the ADDIE (Analyze, Design, Development, Implementation and Evaluate) procedure. This study developed a tsunami early warning system that works effectively with a fast average response time of 13.48 seconds to download tsunami potential information on the BMKG website and proceed it to trigger the loudspeaker at places of worship.